Restore missing ApplicationSearch join clause for Maniphest

Summary: See IRC. This got dropped in the order refactoring.

Test Plan: Ordered Maniphest search results by a custom field.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D12614

src/infrastructure/query/policy/PhabricatorCursorPagedPolicyAwareQuery.php

@@ -226,6 +226,7 @@ abstract class PhabricatorCursorPagedPolicyAwareQuery
   protected function buildJoinClauseParts(AphrontDatabaseConnection $conn) {
     $joins = array();
     $joins[] = $this->buildEdgeLogicJoinClause($conn);
+    $joins[] = $this->buildApplicationSearchJoinClause($conn);
     return $joins;
   }