Replace some forgotten references to skins/default (#1488591)

Thomas Bruederli

2012-08-09 aff970b5d3c71d3422852e49dbfcdbf5c8e8bbe0

 program/include/rcube_message_part.php

@@ -19,9 +19,6 @@
 | Author: Thomas Bruederli <roundcube@gmail.com>                        |
 | Author: Aleksander Machniak <alec@alec.pl>                            |
 +-----------------------------------------------------------------------+

 $Id$

*/