Add view mixin to make sure a subclass can't override its

parent's get_queryset method.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/documents/views/document_views.py

@@ -63,8 +63,7 @@ class DocumentListView(SingleObjectListView):
         }
 
     def get_queryset(self):
-        self.queryset = self.get_document_queryset().filter(is_stub=False)
-        return super(DocumentListView, self).get_queryset()
+        return self.get_document_queryset().filter(is_stub=False)
 
 
 class DeletedDocumentListView(DocumentListView):