Fix method visibility for PhabricatorApplicationSearchEngine methods

Summary: Ref T6822.

Test Plan: Visual inspection. These methods are only called from within the `PhabricatorApplicationSearchEngine` class.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T6822

Differential Revision: https://secure.phabricator.com/D11242

src/applications/oauthserver/query/PhabricatorOAuthServerClientSearchEngine.php

@@ -7,7 +7,7 @@ final class PhabricatorOAuthServerClientSearchEngine
     return pht('OAuth Clients');
   }
 
-  public function getApplicationClassName() {
+  protected function getApplicationClassName() {
     return 'PhabricatorOAuthServerApplication';
   }
 
@@ -55,7 +55,7 @@ final class PhabricatorOAuthServerClientSearchEngine
     return '/oauthserver/'.$path;
   }
 
-  public function getBuiltinQueryNames() {
+  protected function getBuiltinQueryNames() {
     $names = array();
 
     if ($this->requireViewer()->isLoggedIn()) {