update copyright range on main doc page

git-svn-id: svn+ssh://jackaudio.org/trunk/jack@3111 0c269be4-1314-0410-8aa9-9f06e86f4224

doc/mainpage.dox

@@ -140,7 +140,7 @@ porting-guide document.
 
 @section license License
 
-Copyright (C) 2001-2003 by Paul Davis and others.
+Copyright (C) 2001-2008 by Paul Davis and others.
 
 JACK is free software; you can redistribute it and/or modify it under
 the terms of the GNU GPL and LGPL licenses as published by the Free