As per
https://lintian.debian.org/tags/copyright-not-using-common-license-for-gpl
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
General Public License for more details.
You should have received a copy of the GNU General Public License
-along with this program. If not, see <http://www.gnu.org/licenses/>.
+along with this program: A copy of this licence can be found on
+your Debian system in /usr/share/common-licenses/GPL-3.
+If not, see <http://www.gnu.org/licenses/>.