CHeck for current shelves attr before querying for it

bookwyrm/templatetags/bookwyrm_tags.py

@@ -70,6 +70,9 @@ def related_status(notification):
 @register.simple_tag(takes_context=True)
 def active_shelf(context, book):
     """check what shelf a user has a book on, if any"""
+    if hasattr(book, "current_shelves"):
+        return book.current_shelves[0]
+
     shelf = (
         models.ShelfBook.objects.filter(
             shelf__user=context["request"].user,