fix(users): Update hook needs to check existence of display_name as well

flaschengeist/controller/userController.py

@@ -78,6 +78,8 @@ def reset_password(token: str, password: str):
 @Hook
 def update_user(user):
     current_app.config["FG_AUTH_BACKEND"].update_user(user)
+    if not user.display_name:
+        user.display_name = "{} {}.".format(user.firstname, user.lastname[0])
     db.session.commit()