Fix bad ancestor classname

Summary: Derped this up in D11234.

Test Plan: Ran `bin/search index --all`.

Reviewers: joshuaspence

Reviewed By: joshuaspence

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D11273

src/applications/search/management/PhabricatorSearchManagementIndexWorkflow.php

@@ -115,7 +115,7 @@ final class PhabricatorSearchManagementIndexWorkflow
 
   private function loadPHIDsByTypes($type) {
     $indexers = id(new PhutilSymbolLoader())
-      ->setAncestorClass('PhabricatorSearchObjectIndexer')
+      ->setAncestorClass('PhabricatorSearchDocumentIndexer')
       ->loadObjects();
 
     $phids = array();