R1:a94eee694b73

Fix empty titles on pages without application names

Summary: Fixes T3195. Currently, we show `[] Phabricator` on the homepage with unicode glyphs off.

Test Plan:
Viewed home page and application pages with glyphs on and off. Saw:

| | Unicode | No Unicode |
| | ------- | ---------- |
| Home | Empty | Empty |
| ---- | | |
| Differential | Gear | Differential |
| ---- | | |

Reviewers…