Skip confirmation when deleting empty shelves
Created originally on Bitbucket by nick_timkovich (Nick Timkovich)
Not quite #1955 (closed), but a half-step towards it.
When deleting empty shelves that I no longer want, it's a tiny bit disconcerting to see a confirmation if I really want to delete it. It would be nice if THG noticed it was empty and not bother asking as the only "irrecoverable loss" would be the shelf name.