Handle if user doesn't have org id when importing group

circle/dashboard/models.py

@@ -339,6 +339,7 @@ class GroupProfile(AclBase):
 
             for org_id in data["users"]:
                 try:
+                    if org_id is not None:
                         user = Profile.objects.get(org_id=org_id).user
                         user.groups.add(group)
                 except ObjectDoesNotExist: