Don't display empty shelves on user page

bookwyrm/views/user.py

@@ -31,12 +31,13 @@ class User(View):
         shelf_preview = []
 
         # only show shelves that should be visible
-        shelves = user.shelf_set
         is_self = request.user.id == user.id
         if not is_self:
             shelves = models.Shelf.privacy_filter(
                 request.user, privacy_levels=["public", "followers"]
             ).filter(user=user, books__isnull=False)
+        else:
+            shelves = user.shelf_set.filter(books__isnull=False).distinct()
 
         for user_shelf in shelves.all()[:3]:
             shelf_preview.append(