Sync AlekSIS groups to Django groups on registration of existing Persons

Closes #752 (closed)

Maybe there is a more suitable location for those two lines? In some function that is always executed on registration, not just through this form (e.g. through LDAP login).

aleksis/core/forms.py

@@ -659,7 +659,11 @@ class AccountRegisterForm(SignupForm, ExtensibleForm):
                 if get_site_preferences()["account__auto_create_person"]:
                     Person.objects.create(user=user, **data)
         if person_qs.exists():
-            person_qs.update(user=user, **data)
+            person = person_qs.first()
+            for field, value in data.items():
+                setattr(person, field, value)
+            person.user = user
+            person.save()
         self.custom_signup(request, user)
         setup_user_email(request, user, [])
         return user