VLCMedia: protect 'parse' against missing p_md instance (close #8718)
VLCMedia: protect 'parse' against missing p_md instance (close #8718)

hpsoar/VLCKit,waterskier2007/VLCKit,hpsoar/VLCKit,kamcord/VLCKit,kamcord/VLCKit,programming086/VLCKit,siuying/VLCKit,simon1984/test,siuying/VLCKit,larrytin/VLCKit,waterskier2007/VLCKit,simon1984/test,siuying/VLCKit,simon1984/test,strukturag/VLCKit,waterskier2007/VLCKit,CollabraMusic/VLCKit,brion/VLCKit,strukturag/VLCKit,kamcord/VLCKit,larrytin/VLCKit,programming086/VLCKit,CollabraMusic/VLCKit,i386/vlckit,CollabraMusic/VLCKit