Fix commenting on Persons with no user

aleksis/apps/abi/forms.py

@@ -284,6 +284,7 @@ class CommentForm(forms.ModelForm):
         self.allowed_persons_with_review = (
             AbiPerson.objects.filter(member_of__in=self.allowed_groups_with_review)
             .exclude(pk=self.person.pk)
+            .exclude(person__user=None)
             .distinct()
         )
         allowed_persons = self.allowed_persons | self.allowed_persons_with_review