Remove spinner GIF for loading tokenizers

Summary: Ref T4420. I think the border is good enough without this spinny thing, and it needs a lot of code.

Test Plan: Used typeahead.

Reviewers: chad, btrahan

Reviewed By: chad

CC: chad, aran

Maniphest Tasks: T4420

Differential Revision: https://secure.phabricator.com/D8249