Copyright for mrtg source package in Focal

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: mrtg
Source: http://oss.oetiker.ch/mrtg/

Files: *
Copyright: Copyright (c) 1996-2001 Tobias Oetiker and all the Contributers to MRTG
 All rights reserved.
License: GPL-2+

Files: debian/*
Copyright: Copyright (C) 2009-2019, Sandro Tosi 
License: GPL-2+

License: GPL-2+
 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 License, or (at your option)
 any later version.
 .
 This program 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.
 .
 On Debian GNU/Linux systems, you can find a copy of the GNU General Public
 License v2 in /usr/share/common-licenses/GPL-2.