mkv: an edition with no duration is OK if there's some chapter codec
mkv: an edition with no duration is OK if there's some chapter codec

The chapter codec will likely request a jump to another Segment/Edition

Signed-off-by: Jean-Baptiste Kempf <7b85a41a628204b76aba4326273a3ccc74bd009a@videolan.org>

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc