auth_fc: save forced mapping of first_name and last_name (#52855)

src/authentic2_auth_fc/backends.py

@@ -85,6 +85,7 @@ class FcBackend(ModelBackend):
                 user.last_name = user_info['family_name']
                 updated.append('family name: "%s"' % user_info['family_name'])
             if updated:
+                user.save()
                 logger.debug('updated (%s)', ' - '.join(updated))
             utils.apply_user_info_mappings(user, user_info)
             return user