update debian/copyright file, we are now under GPLv3

debian/copyright

-This package was debianized by Yann L.B. asterix@lagaule.org on
+This package was debianized by Yann Leboulanger asterix@lagaule.org on
 Wed, 16 Jun 2005 20:00:00 +0100.
 
 It was downloaded from:
@@ -10,12 +10,11 @@ Upstream Authors:
       - Travis Shirk <travis@pobox.com>
  
 
-Copyright: (c) 2003-2006 Gajim Team
+Copyright: (c) 2003-2009 Gajim Team
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
+the Free Software Foundation; version 3
  
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of