Actually enforce auth.lock-config
Summary: Forgot to post this after D20394. Fixes T7667.
Test Plan:
- Edited some providers with the config locked and unlocked.
- Opened the edit form with the config unlocked, locked the config, then saved, and got a sensible error:
Reviewers: epriestley
Reviewed By: epriestley
Subscribers: Korvin
Maniphest Tasks: T7667
Differential Revision: https://secure.phabricator.com/D20645