Made purgeDeletedFiles.php delete files still in the public zone.

* This makes purges more useful since the file won't come back.
* This only applies for files that are confirmed to already be
  in the deleted zone too. This is for sanity.

Change-Id: I60316c1d9323347d09607e36a334fc5eb0b6a2e7
(cherry picked from commit 28483205c91a9110355a24c26058121dc1bfeb83)