R1:46d496b8cc06

Fix error for URL's that could mean several commits

Summary: Ref T13001, URLs that return multiple commits should show a list of those commits. Not sure if the actual list looks very pretty this way, but was wondering if this approach was vaguely correct.

Test Plan:
- Navigate to `install/rPbd3c23`
- User should see a list view providing links to `install/rPbd3c2355e8e2b220ae5e3cbfe4a057c8088c6a38` and `install/rPbd3c239d5aada68a31db5742bbb8ec099074a561`

Reviewers: epriestley, #blessed_reviewers…