Apply sprite sheet changes to Phabricator

Summary: Basically a one line change, plus a regen. This should be the last full-rewrite these things get since they'll stop fully rehashing all the time now.

Test Plan: See D5964.

Reviewers: chad, btrahan

Reviewed By: chad

CC: aran

Differential Revision: https://secure.phabricator.com/D5965