tv4play: find id of the video
tv4play: find id of the video

fixes #674

dalgr/svtplay-dl,olof/svtplay-dl,dalgr/svtplay-dl,olof/svtplay-dl,spaam/svtplay-dl,selepo/svtplay-dl,spaam/svtplay-dl,selepo/svtplay-dl