R1:3d8d98bd8deb

Probably (?) fix two very old project slug migrations

Summary: Fixes T12020. These callsites to `getPhrictionSlug()` were missed when that method was removed. They're very old (early 2014, late 2011).

Test Plan:
These are tricky to test because the migrations are so ancient, but `bin/storage upgrade --force --apply phabricator:20140521.projectslug.2.mig.php` gave me //plausible// results.

The other migration is so ancient that it can't apply to a modern database so I'm just kind of winging that one. We…