Don't link objects after a hyphen

Summary: Fixes T5714. Don't link objects when their names appear after a hyphen.

Test Plan: Tested `F123` (link), `(F123)` (link), `G12-F123` (no link).

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T5714

Differential Revision: https://secure.phabricator.com/D10456