Codestyle enhancements

app/settings/tasks.py

@@ -8,6 +8,6 @@ def delete_user(user_id, *args, **kwargs):
     with kwargs['app'].app_context():
         user = User.query.get(user_id)
         if user is None:
-            raise Exception('User {} not found'.format(user_id))
+            raise Exception(f'User {user_id} not found')
         user.delete()
         db.session.commit()