Wrong items left to curate for third parties without items to curate

## 🎉 Description

When the collection has no items to curate, it shows that it has `1/` items to curated, which is inaccurate. It should show `0/0`.

Steps to reproduce:
- Create a third party collection
- Add an item
- Publish the item
- Go to the curation tab, approve the item and check that the remaining items are set as `1/`