Prevent users from disabling repository builtin URIs
Summary:
Ref T10923. Currently, users can disable or enable builtin URIs, but this doesn't actually do anything.
The behavior of "disable" has changed a bit over time and might need some further refinement, but it's currently meaningless for builtin URIs. Prevent adjustment of it. If users want to hide a URI, they should set "Display: Hidden" instead.
Test Plan:
- Disabled/enabled a non-builtin URI.
- Tried to disable a builtin URI, saw greyed out UI and got a helpful error message.
Reviewers: chad
Reviewed By: chad
Subscribers: eadler
Maniphest Tasks: T10923
Differential Revision: https://secure.phabricator.com/D15899