Remove mention of Phabricator in the Auth setup check

Summary:
The authentication setup check, available at <PHORGE_URL>/config/issue/auth.config-unlocked/,
contained a reference to Phabricator in the prompt of the command line hint to resolve the issue.
Similar checks only showed the prompt symbol, not the directory, so this one was changed to match.

Ref T15006

Test Plan:

• Run ./bin/auth unlock
• Visit <PHORGE_URL>/config/issue/auth.config-unlocked/
• Notice that, with this patch, "phabricator" no longer appears in the prompt prefix for the suggested fix command at the end of the page.

Reviewers: O1 Blessed Committers, valerio.bozzolan, speck

Reviewed By: O1 Blessed Committers, valerio.bozzolan, speck

Subscribers: avivey, tobiaswiese, Matthew, valerio.bozzolan, Cigaryno

Maniphest Tasks: T15006

Differential Revision: https://we.phorge.it/D25425