update_track_timescale bug fix
update_track_timescale bug fix

after adjusting the duration of the last clip frame, need to update dts in
addition to scaled_dts.

kaltura/nginx-vod-module,kaltura/nginx-vod-module,kaltura/nginx-vod-module,kaltura/nginx-vod-module,kaltura/nginx-vod-module,kaltura/nginx-vod-module