Fix concurrency issue in entry sorting properly

[Gargaj]

https://github.com/Gargaj/wuhu/blob/30f04d527fe9af5bf4292d2bbecfcbbf412001fd/www_admin/plugins/draggable_compoentries/ajax_reorder.php#L16-L19

Remove deleted entries from list, add new entries to the end of the list, never fail.