debian/copyright: Drop GPL-2.0+ license as I couldn't find any headers mention that.

debian/copyright

@@ -6,7 +6,7 @@ Files: *
 Copyright: 2012-2015 LXQt team
            2010-2012 Razor team
            2010-2014 Petr Vanek <petr@scribus.info>
-License: GPL-2.0+ and LGPL-2.1+
+License: LGPL-2.1+
 
 Files: debian/*
 Copyright: 2014-2015 Alf Gaida <agaida@siduction.org>
@@ -25,21 +25,6 @@ License: LGPL-2.1+
  Lesser General Public License for more details.
  .
  On Debian systems, the complete text of the GNU Lesser General
- Public License version 2.1 can be found in "/usr/share/common-licenses/LGPL-2.1".
+ Public License version 2.1 can be found in
+ "/usr/share/common-licenses/LGPL-2.1".
 
-License: GPL-2.0+
- This package 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 License, or
- (at your option) any later version.
- .
- This package is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- GNU General Public License for more details.
- .
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>
- .
- On Debian systems, the complete text of the GNU General
- Public License version 2 can be found in "/usr/share/common-licenses/GPL-2".