R1:8fbb411a9a72

Respect user/pass flags to bin/storage for direct DatabaseRef-based queries

Summary:
Ref T11893. Previously, we excuted all `bin/storage` queries through `StorageManagementAPI` objects.

After D16848, we execute some queries through `PhabricatorDatabaseRef`. However, the refs we use weren't getting passed the `-u` / `-p` flags correctly, for specifying alternate administrative credentials.

Test Plan:
- Created a second account (`trunk`).
- Ran `bin/storage -u trunk`.
- Made libphutil throw when not…