add code to drop old databases

Summary: these existed once, are no more, and don't get cleaned up in the current code path

Test Plan: storage destroy --dryrun -- noted the correct database names

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2237

Differential Revision: https://secure.phabricator.com/D4329

src/infrastructure/storage/management/workflow/PhabricatorStorageManagementDestroyWorkflow.php

@@ -53,6 +53,9 @@ final class PhabricatorStorageManagementDestroyWorkflow
     } else {
       $databases = $api->getDatabaseList($patches);
       $databases[] = $api->getDatabaseName('meta_data');
+      // These are legacy databases that were dropped long ago. See T2237.
+      $databases[] = $api->getDatabaseName('phid');
+      $databases[] = $api->getDatabaseName('directory');
     }
 
     foreach ($databases as $database) {