Copyright for ruby-gsl source package in Bullseye

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: rb-gsl
Upstream-Contact: https://github.com/SciRuby/rb-gsl/issues
Source: https://github.com/SciRuby/rb-gsl
Comment: The upstream tarball has been repacked to remove the rdoc/ directory
 containing files under the (non-free) GNU Documentation license with
 invariant sections. See debian/README.source for details.
Files-Excluded: rdoc
 tmp

Files: *
Copyright: 2001-2006, Yoshiki Tsunesada
License: GPL-2

Files: ext/gsl_native/histogram_find.c
Copyright: 1996-2000, Brian Gough
License: GPL-2+

Files: ext/gsl_native/histogram_oper.c
Copyright: 2000, Simone Piccardi
License: GPL-2+

Files: debian/*
Copyright: 2010 Deepak Tripathi 
           2013 Cédric Boutillier 
           2019,2020 Debian Ruby Extras Maintainers 
License: GPL-2
Comment: The Debian packaging is licensed under the same terms as the source.

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; version 2 dated June, 1991.
Comment: On Debian systems, the complete text of version 2 of the GNU General
 Public License can be found in '/usr/share/common-licenses/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; version 2 dated June, 1991, or (at
 your option) any later version.
Comment: On Debian systems, the complete text of version 2 of the GNU General
 Public License can be found in '/usr/share/common-licenses/GPL-2'.