Call the indexer for hidden pages

This makes sure that the indexer is also called for hidden pages so they
aren't missing in the title index and digest subscriptions work for
them, too. Hidden pages are already filtered from the search results.

inc/template.php

@@ -988,8 +988,6 @@ function tpl_indexerWebBug(){
     global $INFO;
     if(!$INFO['exists']) return false;
 
-    if(isHiddenPage($ID)) return false; //no need to index hidden pages
-
     $p = array();
     $p['src']    = DOKU_BASE.'lib/exe/indexer.php?id='.rawurlencode($ID).
         '&'.time();