Avoid exception when arrowing down past end of list

I have a feeling that urwid has a more elegant way to handle scrolling
behavior, but it wasn't very obvious, so this works.

Signed-off-by: Andy Grover <agrover@redhat.com>
Fixup debian/copyright to refer to correct license

The package is distributed under the GNU Affero GPL, so the
debian copyright file should refer to the correct license.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@risingtidesystems.com>
Merge branch 'master' into dev
Merge remote branch 'gh/master' into dev