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 probably have essentially no installs which will ever apply it again, though.

Reviewers: chad, avivey

Reviewed By: avivey

Maniphest Tasks: T12020

Differential Revision: https://secure.phabricator.com/D17060