Ensure that media info inherits the sequence tags

[diogoazevedos]

Fix the regression introduced via #1506 as mentioned at #1506 (comment).

[diogoazevedos]

I believe the same is missing for MKV, at

nginx-vod-module/vod/mkv/mkv_format.c

Line 899 in 26f0687

vod_memzero(cur_track, sizeof(*cur_track));

we could introduce

// inherit the sequence tags
cur_track->media_info.tags = sequence->tags;