Copyright for bwbar source package in Focal

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: bwbar
Source: https://www.kernel.org/pub/software/web/bwbar/

Files: *
Copyright: 1999-2006 H. Peter Anvin
License: GPL-2.0+

Files: debian/*
Copyright: 2001 Scott M. Dier 
           2006 Julien Danjou 
           2016-2017 Tobias Frost 
License: GPL-2.0+

License: GPL-2.0+
 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, Inc., 51 Franklin St, Fifth Floor, Boston,
 MA 02110-1301, USA.  either version 2 of the License, or (at your option)
 any later version; incorporated herein by reference.
 .
 On Debian systems, the complete text of the GNU General Public
 License can be found in /usr/share/common-licenses/GPL-2 file.