Fix auto_create_subscription

(cherry picked from commit 8d4fd5b)

apps/user/models.py

@@ -137,7 +137,7 @@ def send_user_info_to_mixpanel(sender, instance=None, created=False, **kwargs):
 def auto_create_subscription(sender, instance=None, created=False, **kwargs):
     try:
         es = EmailSubscription.objects.get(email=instance.email)
-        if not es.user:
+        if not hasattr(instance, 'email_subscription'):
             es.user = instance
             es.save()
     except EmailSubscription.DoesNotExist: