We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Doublon pour les logs en couleur dans l'env de dev
Sur mon environnement de dev, les logs en couleur apparaissent en double : dans leur version couleur et puis dans leur version standard.

![image](https://user-images.githubusercontent.com/6664636/132962287-3983d73d-dae7-4f95-b7c1-ed86c63c51ea.png)

OS : Ubuntu Budgie 20.04

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `zds/settings/dev.py`
Content:
```
1 from colorlog import ColoredFormatter
2 
3 from .abstract_base import *
4 
5 DEBUG = True
6 
7 # NOTE: Can be removed once Django 3 is used
8 ALLOWED_HOSTS = [".localhost", "127.0.0.1", "[::1]"]
9 
10 INSTALLED_APPS += (
11     "debug_toolbar",
12     "django_extensions",
13 )
14 
15 MIDDLEWARE = (
16     "debug_toolbar.middleware.DebugToolbarMiddleware",
17     "zds.middlewares.nocacheindevmiddleware.NoCacheInDevMiddleware",
18 ) + MIDDLEWARE
19 
20 LOGGING = {
21     "version": 1,
22     "disable_existing_loggers": False,
23     "formatters": {
24         "verbose": {
25             "()": ColoredFormatter,
26             "format": "%(log_color)s %(levelname)s %(reset)s %(bold_black)s%(name)s%(reset)s %(message)s",
27             "log_colors": {
28                 "DEBUG": "fg_white,bg_black",
29                 "INFO": "fg_black,bg_bold_white",
30                 "WARNING": "fg_black,bg_bold_yellow",
31                 "ERROR": "fg_bold_white,bg_bold_red",
32                 "CRITICAL": "fg_bold_white,bg_bold_red",
33             },
34         },
35         "django.server": {
36             "()": ColoredFormatter,
37             "format": "%(log_color)s%(message)s",
38             "log_colors": {
39                 "INFO": "bold_black",
40                 "WARNING": "bold_yellow",
41                 "ERROR": "bold_red",
42                 "CRITICAL": "bold_red",
43             },
44         },
45     },
46     "handlers": {
47         "console": {
48             "level": "DEBUG",
49             "class": "logging.StreamHandler",
50             "formatter": "verbose",
51         },
52         "django.server": {
53             "level": "DEBUG",
54             "class": "logging.StreamHandler",
55             "formatter": "django.server",
56         },
57     },
58     "loggers": {
59         "django": {
60             "level": "INFO",
61             "handlers": ["console"],
62         },
63         "django.server": {
64             "level": "INFO",
65             "handlers": ["django.server"],
66             "propagate": False,
67         },
68         "zds": {
69             "level": "INFO",
70             "handlers": ["console"],
71         },
72     },
73 }
74 
75 ZDS_APP["site"]["url"] = "http://127.0.0.1:8000"
76 ZDS_APP["site"]["dns"] = "127.0.0.1:8000"
77 
78 ZDS_APP["very_top_banner"] = {
79     "background_color": "#666",
80     "border_color": "#353535",
81     "color": "white",
82     "message": "Version locale",
83     "slug": "version-locale",
84 }
85
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/zds/settings/dev.py b/zds/settings/dev.py
--- a/zds/settings/dev.py
+++ b/zds/settings/dev.py
@@ -55,10 +55,12 @@
             "formatter": "django.server",
         },
     },
+    "root": {
+        "handlers": ["console"],
+    },
     "loggers": {
         "django": {
             "level": "INFO",
-            "handlers": ["console"],
         },
         "django.server": {
             "level": "INFO",
@@ -67,7 +69,6 @@
         },
         "zds": {
             "level": "INFO",
-            "handlers": ["console"],
         },
     },
 }

{"golden_diff": "diff --git a/zds/settings/dev.py b/zds/settings/dev.py\n--- a/zds/settings/dev.py\n+++ b/zds/settings/dev.py\n@@ -55,10 +55,12 @@\n             \"formatter\": \"django.server\",\n         },\n     },\n+    \"root\": {\n+        \"handlers\": [\"console\"],\n+    },\n     \"loggers\": {\n         \"django\": {\n             \"level\": \"INFO\",\n-            \"handlers\": [\"console\"],\n         },\n         \"django.server\": {\n             \"level\": \"INFO\",\n@@ -67,7 +69,6 @@\n         },\n         \"zds\": {\n             \"level\": \"INFO\",\n-            \"handlers\": [\"console\"],\n         },\n     },\n }\n", "issue": "Doublon pour les logs en couleur dans l'env de dev\nSur mon environnement de dev, les logs en couleur apparaissent en double : dans leur version couleur et puis dans leur version standard.\r\n\r\n![image](https://user-images.githubusercontent.com/6664636/132962287-3983d73d-dae7-4f95-b7c1-ed86c63c51ea.png)\r\n\r\nOS : Ubuntu Budgie 20.04\n", "before_files": [{"content": "from colorlog import ColoredFormatter\n\nfrom .abstract_base import *\n\nDEBUG = True\n\n# NOTE: Can be removed once Django 3 is used\nALLOWED_HOSTS = [\".localhost\", \"127.0.0.1\", \"[::1]\"]\n\nINSTALLED_APPS += (\n    \"debug_toolbar\",\n    \"django_extensions\",\n)\n\nMIDDLEWARE = (\n    \"debug_toolbar.middleware.DebugToolbarMiddleware\",\n    \"zds.middlewares.nocacheindevmiddleware.NoCacheInDevMiddleware\",\n) + MIDDLEWARE\n\nLOGGING = {\n    \"version\": 1,\n    \"disable_existing_loggers\": False,\n    \"formatters\": {\n        \"verbose\": {\n            \"()\": ColoredFormatter,\n            \"format\": \"%(log_color)s %(levelname)s %(reset)s %(bold_black)s%(name)s%(reset)s %(message)s\",\n            \"log_colors\": {\n                \"DEBUG\": \"fg_white,bg_black\",\n                \"INFO\": \"fg_black,bg_bold_white\",\n                \"WARNING\": \"fg_black,bg_bold_yellow\",\n                \"ERROR\": \"fg_bold_white,bg_bold_red\",\n                \"CRITICAL\": \"fg_bold_white,bg_bold_red\",\n            },\n        },\n        \"django.server\": {\n            \"()\": ColoredFormatter,\n            \"format\": \"%(log_color)s%(message)s\",\n            \"log_colors\": {\n                \"INFO\": \"bold_black\",\n                \"WARNING\": \"bold_yellow\",\n                \"ERROR\": \"bold_red\",\n                \"CRITICAL\": \"bold_red\",\n            },\n        },\n    },\n    \"handlers\": {\n        \"console\": {\n            \"level\": \"DEBUG\",\n            \"class\": \"logging.StreamHandler\",\n            \"formatter\": \"verbose\",\n        },\n        \"django.server\": {\n            \"level\": \"DEBUG\",\n            \"class\": \"logging.StreamHandler\",\n            \"formatter\": \"django.server\",\n        },\n    },\n    \"loggers\": {\n        \"django\": {\n            \"level\": \"INFO\",\n            \"handlers\": [\"console\"],\n        },\n        \"django.server\": {\n            \"level\": \"INFO\",\n            \"handlers\": [\"django.server\"],\n            \"propagate\": False,\n        },\n        \"zds\": {\n            \"level\": \"INFO\",\n            \"handlers\": [\"console\"],\n        },\n    },\n}\n\nZDS_APP[\"site\"][\"url\"] = \"http://127.0.0.1:8000\"\nZDS_APP[\"site\"][\"dns\"] = \"127.0.0.1:8000\"\n\nZDS_APP[\"very_top_banner\"] = {\n    \"background_color\": \"#666\",\n    \"border_color\": \"#353535\",\n    \"color\": \"white\",\n    \"message\": \"Version locale\",\n    \"slug\": \"version-locale\",\n}\n", "path": "zds/settings/dev.py"}], "after_files": [{"content": "from colorlog import ColoredFormatter\n\nfrom .abstract_base import *\n\nDEBUG = True\n\n# NOTE: Can be removed once Django 3 is used\nALLOWED_HOSTS = [\".localhost\", \"127.0.0.1\", \"[::1]\"]\n\nINSTALLED_APPS += (\n    \"debug_toolbar\",\n    \"django_extensions\",\n)\n\nMIDDLEWARE = (\n    \"debug_toolbar.middleware.DebugToolbarMiddleware\",\n    \"zds.middlewares.nocacheindevmiddleware.NoCacheInDevMiddleware\",\n) + MIDDLEWARE\n\nLOGGING = {\n    \"version\": 1,\n    \"disable_existing_loggers\": False,\n    \"formatters\": {\n        \"verbose\": {\n            \"()\": ColoredFormatter,\n            \"format\": \"%(log_color)s %(levelname)s %(reset)s %(bold_black)s%(name)s%(reset)s %(message)s\",\n            \"log_colors\": {\n                \"DEBUG\": \"fg_white,bg_black\",\n                \"INFO\": \"fg_black,bg_bold_white\",\n                \"WARNING\": \"fg_black,bg_bold_yellow\",\n                \"ERROR\": \"fg_bold_white,bg_bold_red\",\n                \"CRITICAL\": \"fg_bold_white,bg_bold_red\",\n            },\n        },\n        \"django.server\": {\n            \"()\": ColoredFormatter,\n            \"format\": \"%(log_color)s%(message)s\",\n            \"log_colors\": {\n                \"INFO\": \"bold_black\",\n                \"WARNING\": \"bold_yellow\",\n                \"ERROR\": \"bold_red\",\n                \"CRITICAL\": \"bold_red\",\n            },\n        },\n    },\n    \"handlers\": {\n        \"console\": {\n            \"level\": \"DEBUG\",\n            \"class\": \"logging.StreamHandler\",\n            \"formatter\": \"verbose\",\n        },\n        \"django.server\": {\n            \"level\": \"DEBUG\",\n            \"class\": \"logging.StreamHandler\",\n            \"formatter\": \"django.server\",\n        },\n    },\n    \"root\": {\n        \"handlers\": [\"console\"],\n    },\n    \"loggers\": {\n        \"django\": {\n            \"level\": \"INFO\",\n        },\n        \"django.server\": {\n            \"level\": \"INFO\",\n            \"handlers\": [\"django.server\"],\n            \"propagate\": False,\n        },\n        \"zds\": {\n            \"level\": \"INFO\",\n        },\n    },\n}\n\nZDS_APP[\"site\"][\"url\"] = \"http://127.0.0.1:8000\"\nZDS_APP[\"site\"][\"dns\"] = \"127.0.0.1:8000\"\n\nZDS_APP[\"very_top_banner\"] = {\n    \"background_color\": \"#666\",\n    \"border_color\": \"#353535\",\n    \"color\": \"white\",\n    \"message\": \"Version locale\",\n    \"slug\": \"version-locale\",\n}\n", "path": "zds/settings/dev.py"}]}