Copyright for ddtc source package in Xenial

This is ddtc.

Copyright (c) 2001-2003 Nicolas Bertolissio 

This 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, or (at your option) any later
version.

This 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 with
your Debian GNU/Linux system, in /usr/share/common-licenses/GPL.  If
not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth
Floor, Boston, MA 02110-1301, USA.