Update profile url workaround (#459)

* Try something for test

* Update fix

* Update fix

* Lint fix

amundsen_application/models/user.py

-from typing import Dict
+from typing import Dict, Optional
 
 from amundsen_common.models.user import UserSchema, User
 from flask import current_app as app
 from marshmallow import ValidationError
 
 
+def _str_no_value(s: Optional[str]) -> bool:
+    # Returns True if the given string is None or empty
+    if not s:
+        return True
+    if len(s.strip()) == 0:
+        return True
+    return False
+
+
 def load_user(user_data: Dict) -> User:
     try:
         schema = UserSchema()
-        # To make sure we pass frontend configuration to amundsen common models
-        user_data['GET_PROFILE_URL'] = app.config['GET_PROFILE_URL']
+        # In order to call 'GET_PROFILE_URL' we make sure the user id exists
+        if _str_no_value(user_data.get('user_id')):
+            user_data['user_id'] = user_data.get('email')
+        # Add profile_url from optional 'GET_PROFILE_URL' configuration method.
+        # This methods currently exists for the case where the 'profile_url' is not included
+        # in the user metadata.
+        if _str_no_value(user_data.get('profile_url')) and app.config['GET_PROFILE_URL']:
+            user_data['profile_url'] = app.config['GET_PROFILE_URL'](user_data['user_id'])
         data, errors = schema.load(user_data)
         return data
     except ValidationError as err: