ttml demux: drop metadata tag inside p to avoid conflict
ttml demux: drop metadata tag inside p to avoid conflict

As there is plaintext inside the metatdata tag, when there
is one inside of the p span, we just drop it to avoid its
display.

Signed-off-by: Hugo Beauzée-Luyssen <3faf7ed52fa83d583fc670a96bcf92da270d0767@beauzee.fr>

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