Fix copyright file to reduce lintian complains.

debian/copyright

@@ -119,7 +119,7 @@ Copyright: 1987, Digital Equipment Corporation, Maynard, Massachusetts
            2002, Red Hat Inc
            1987-1998, The Open Group
            1988, Wyse Technology, Inc., San Jose, Ca
-License: GPL-2+ or MIT/X11
+License: GPL-2+_MIT/X11
  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 of the
@@ -202,7 +202,7 @@ License: Permissive
 Files: po/rw.po
 Copyright: 2005, Free Software Foundation, Inc
            2001-2002, Havoc Pennington, Red Hat, Inc., and others
-License: GPL-2+ or LGPL-2.1+ or MPL-1.1
+License: MPL-1.1_GPL-2+_LGPL-2.1+
  ***** BEGIN LICENSE BLOCK *****
  Version: MPL 1.1/GPL 2.0/LGPL 2.1
  .