Show "Broken" status if present, regardless of build failure

Summary: This ensures releases show as "Broken" if they've been marked as such, even if there's a failed build against them.

Test Plan: Tested the behaviour locally by marking a failed release as broken.

Reviewers: waynea, #koi

Reviewed By: waynea, #koi

JIRA Issues: KOI-1031

Differential Revision: https://code.pageuppeople.com/D3592

Risk Rating: 1