When a repository is inactive, mark its handle as "closed"

Summary: See downstream https://phabricator.wikimedia.org/T182232. We currently don't mark repository handles as closed.

Test Plan: Mentioned two repositories with R1 (active) and R2 (inactive). After patch, saw R2 visually indicated as closed/inactive.

Reviewers: amckinley

Reviewed By: amckinley

Differential Revision: https://secure.phabricator.com/D20309