prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  🐛(backend) licence not saved during creation video resource
  ## Bug Report
  
  **Problematic Behavior**
  When we create a video and set a licence, the licence is not saved.
  
  [error-licence-2023-09-12 143121.webm](https://github.com/openfun/marsha/assets/25994652/60514ad8-07cd-4390-97c9-21eb3525ecc6)
  
  
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `src/backend/marsha/core/forms.py`
  Content:
  ```
  1 """Marsha forms module."""
  2 from django.core.exceptions import ValidationError
  3 from django.forms import CharField, ModelForm
  4 
  5 from . import models
  6 from .defaults import INITIALIZED
  7 
  8 
  9 class DocumentForm(ModelForm):
  10     """Form to create or update documents."""
  11 
  12     class Meta:
  13         """Meta for DocumentForm."""
  14 
  15         model = models.Document
  16         fields = ["description", "is_public", "lti_id", "playlist", "title"]
  17 
  18 
  19 class VideoForm(ModelForm):
  20     """Form to create or update videos."""
  21 
  22     upload_state = CharField(
  23         max_length=20,
  24         required=False,
  25     )
  26 
  27     class Meta:
  28         """Meta for VideoForm."""
  29 
  30         model = models.Video
  31         fields = [
  32             "description",
  33             "is_public",
  34             "lti_id",
  35             "playlist",
  36             "title",
  37             "upload_state",
  38         ]
  39 
  40     def clean_upload_state(self):
  41         """Check upload_state valid value."""
  42         upload_state = self.cleaned_data["upload_state"]
  43 
  44         if upload_state and upload_state != INITIALIZED:
  45             raise ValidationError(f"{INITIALIZED} is the only accepted value")
  46 
  47         return upload_state
  48
  ```
  --- 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()
  
  ```
  
golden_diff: diff --git a/src/backend/marsha/core/forms.py b/src/backend/marsha/core/forms.py
  --- a/src/backend/marsha/core/forms.py
  +++ b/src/backend/marsha/core/forms.py
  @@ -35,6 +35,7 @@
               "playlist",
               "title",
               "upload_state",
  +            "license",
           ]
   
       def clean_upload_state(self):
  
verification_info: {"golden_diff": "diff --git a/src/backend/marsha/core/forms.py b/src/backend/marsha/core/forms.py\n--- a/src/backend/marsha/core/forms.py\n+++ b/src/backend/marsha/core/forms.py\n@@ -35,6 +35,7 @@\n             \"playlist\",\n             \"title\",\n             \"upload_state\",\n+            \"license\",\n         ]\n \n     def clean_upload_state(self):\n", "issue": "\ud83d\udc1b(backend) licence not saved during creation video resource\n## Bug Report\r\n\r\n**Problematic Behavior**\r\nWhen we create a video and set a licence, the licence is not saved.\r\n\r\n[error-licence-2023-09-12 143121.webm](https://github.com/openfun/marsha/assets/25994652/60514ad8-07cd-4390-97c9-21eb3525ecc6)\r\n\r\n\n", "before_files": [{"content": "\"\"\"Marsha forms module.\"\"\"\nfrom django.core.exceptions import ValidationError\nfrom django.forms import CharField, ModelForm\n\nfrom . import models\nfrom .defaults import INITIALIZED\n\n\nclass DocumentForm(ModelForm):\n    \"\"\"Form to create or update documents.\"\"\"\n\n    class Meta:\n        \"\"\"Meta for DocumentForm.\"\"\"\n\n        model = models.Document\n        fields = [\"description\", \"is_public\", \"lti_id\", \"playlist\", \"title\"]\n\n\nclass VideoForm(ModelForm):\n    \"\"\"Form to create or update videos.\"\"\"\n\n    upload_state = CharField(\n        max_length=20,\n        required=False,\n    )\n\n    class Meta:\n        \"\"\"Meta for VideoForm.\"\"\"\n\n        model = models.Video\n        fields = [\n            \"description\",\n            \"is_public\",\n            \"lti_id\",\n            \"playlist\",\n            \"title\",\n            \"upload_state\",\n        ]\n\n    def clean_upload_state(self):\n        \"\"\"Check upload_state valid value.\"\"\"\n        upload_state = self.cleaned_data[\"upload_state\"]\n\n        if upload_state and upload_state != INITIALIZED:\n            raise ValidationError(f\"{INITIALIZED} is the only accepted value\")\n\n        return upload_state\n", "path": "src/backend/marsha/core/forms.py"}], "after_files": [{"content": "\"\"\"Marsha forms module.\"\"\"\nfrom django.core.exceptions import ValidationError\nfrom django.forms import CharField, ModelForm\n\nfrom . import models\nfrom .defaults import INITIALIZED\n\n\nclass DocumentForm(ModelForm):\n    \"\"\"Form to create or update documents.\"\"\"\n\n    class Meta:\n        \"\"\"Meta for DocumentForm.\"\"\"\n\n        model = models.Document\n        fields = [\"description\", \"is_public\", \"lti_id\", \"playlist\", \"title\"]\n\n\nclass VideoForm(ModelForm):\n    \"\"\"Form to create or update videos.\"\"\"\n\n    upload_state = CharField(\n        max_length=20,\n        required=False,\n    )\n\n    class Meta:\n        \"\"\"Meta for VideoForm.\"\"\"\n\n        model = models.Video\n        fields = [\n            \"description\",\n            \"is_public\",\n            \"lti_id\",\n            \"playlist\",\n            \"title\",\n            \"upload_state\",\n            \"license\",\n        ]\n\n    def clean_upload_state(self):\n        \"\"\"Check upload_state valid value.\"\"\"\n        upload_state = self.cleaned_data[\"upload_state\"]\n\n        if upload_state and upload_state != INITIALIZED:\n            raise ValidationError(f\"{INITIALIZED} is the only accepted value\")\n\n        return upload_state\n", "path": "src/backend/marsha/core/forms.py"}]}