version change: ffmpeg-nonfree to 2.4.1

Signed-off-by: Nico Schottelius <nico@freiheit.schottelius.org>
also update changelog

Signed-off-by: Nico Schottelius <nico@freiheit.schottelius.org>
Merge 'ffmpeg-nonfree-2.4.1' of https://github.com/ungleich/matterhorn-rpms (#9)

Signed-off-by: Lars Kiesow <lkiesow@uos.de>