Fix #198 Error when registering a user that uses a custom user model

rest_auth/registration/views.py

@@ -52,7 +52,7 @@ class RegisterView(CreateAPIView):
         return Response(self.get_response_data(user), status=status.HTTP_201_CREATED, headers=headers)
 
     def perform_create(self, serializer):
-        user = serializer.save(self.request)
+        user = serializer.save()
         if getattr(settings, 'REST_USE_JWT', False):
             self.token = jwt_encode(user)
         else: