update app.py

app.py

@@ -172,7 +172,7 @@ def code_syntax_check_fun(code, language='html'):
         elif check_result['error'] == False:
             return 'Pass'
         else:
-            return 'No check [no language in check_languages]'
+            return f"No check ['{language}' not in check_languages]"
     else:
         return check_result['error']