Made modwsgi groups_for_user consistent with check_password

2b5f848207 based its changes on #19061
that made the is_active attribute mandatory for user models.
The try/except was not removed for the groups_for_user function.

refs #19780

django/contrib/auth/handlers/modwsgi.py

@@ -40,11 +40,7 @@ def groups_for_user(environ, username):
             user = UserModel._default_manager.get_by_natural_key(username)
         except UserModel.DoesNotExist:
             return []
-        try:
-            if not user.is_active:
-                return []
-        except AttributeError as e:
-            # a custom user may not support is_active
+        if not user.is_active:
             return []
         return [force_bytes(group.name) for group in user.groups.all()]
     finally: