Recover from repositories becoming unpullable

Test Plan: If a repository's tracking flag is toggled while it's in queue, we may loop indefinitely.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11296

src/applications/repository/daemon/PhabricatorRepositoryPullLocalDaemon.php

@@ -150,7 +150,8 @@ final class PhabricatorRepositoryPullLocalDaemon
           if (!$repository) {
             $this->log(
               pht('Repository %s is no longer pullable; skipping.', $id));
-            break;
+            unset($queue[$id]);
+            continue;
           }
 
           $monogram = $repository->getMonogram();