use base_manager_name instead of use_for_related_fields (#49189)

docbow_project/docbow/models.py

@@ -175,7 +175,7 @@ FORWARD_PERMISSION = 'FORWARD_DOCUMENT'
 
 
 class DocumentManager(Manager):
-    use_for_related_fields = True
+
     def get_query_set(self):
         '''Prefetch as much as possible.'''
         return super(DocumentManager, self).get_query_set() \
@@ -198,6 +198,7 @@ class Document(Model):
         permissions = (
                 (FORWARD_PERMISSION, _("Can forward documents")),
         )
+        base_manager_name = 'objects'
 
 
     sender = ForeignKey(User, verbose_name=_('Sender'), on_delete=CASCADE,