Remove superfluous calls to all()

bookwyrm/models/shelf.py

@@ -48,7 +48,7 @@ class Shelf(OrderedCollectionMixin, BookWyrmModel):
     @property
     def collection_queryset(self):
         """ list of books for this shelf, overrides OrderedCollectionMixin  """
-        return self.books.all().order_by("shelfbook")
+        return self.books.order_by("shelfbook")
 
     def get_remote_id(self):
         """ shelf identifier instead of id """