Put empty strings instead of None as default values

users/models.py

@@ -59,12 +59,12 @@ class User(AbstractUser):
         data : dict
             Dictionary with user data to update.
         """
-        self.email = data['email']
-        self.first_name = data['first_name']
-        self.last_name = data['last_name']
-        self.phone_number = data['profile']['phone_number']
-        self.address = data['profile']['address']
-        self.comment = data['profile']['section']
+        self.email = data['email'] or ''
+        self.first_name = data['first_name'] or ''
+        self.last_name = data['last_name'] or ''
+        self.phone_number = data['profile']['phone_number'] or ''
+        self.address = data['profile']['address'] or ''
+        self.comment = data['profile']['section'] or ''
 
         for membership_dict in data['memberships']:
             if membership_dict['club'] != 22:  # Med