Remove users ability to remove private messages

[Dave]

The array is an array of usergroupid's which are allowed to delete PM's.

if($vbulletin->GPC['dowhat'] == 'delete' && !in_array($vbulletin->userinfo['usergroupid'], array(6))){ 
  eval(standard_error('You may not delete private messages. <a href="private.php">Return</a>'));
}