fixed plugin updating FS#1804

Ignore-this: c58e8ed83df37a4d4d4bc260ff91033f

darcs-hash:20091123184949-7ad00-ff025fd3efb6c6f07f3e994ce6b3344d03e09ac7.gz

lib/plugins/plugin/classes/ap_update.class.php

 <?php
-
-class ap_update extends ap_manage {
+require_once(DOKU_PLUGIN."/plugin/classes/ap_download.class.php");
+class ap_update extends ap_download {
 
     var $overwrite = true;