Always show repository in Differential emails.

Summary: Ref T5137. A slight modification to D9609, such that the repository is always included in Differential emails. Otherwise "Accepted", "Closed" and "Requested Changes To" emails don't include the repository.

Test Plan: Not tested.

Reviewers: Blessed Reviewers, epriestley

Reviewed By: Blessed Reviewers, epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T5137

Differential Revision: https://secure.phabricator.com/D9728