Copyright for dh-fortran-mod source package in Buster

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/

Files: *
Copyright: 2018 Alastair McKinstry 
License: GPL-3+
 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 3 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.
 .
 You should have received a copy of the GNU General Public License
 along with Dynare.  If not, see .
 .
 On Debian systems, the full text of the GNU General Public License
 version 3 can be found in the file `/usr/share/common-licenses/GPL-3'.