Summary: This migration script is required for D9999, which has already landed.
Test Plan: Ran `./bin/storage upgrade` and can log in again.
Reviewers: #blessed_reviewers, epriestley
Reviewed By: #blessed_reviewers, epriestley
Subscribers: epriestley, Korvin
Differential Revision: https://secure.phabricator.com/D10010
