[api_queue] Removal of top queue when countdown started should stop queue

[calaldees]

If the top level item is removed after the track countdown has started, the next track pops to the top of queue, but it's start time has not been altered. e.g. it will start in 2min. As an admin you manually have to stop the playing and then press play.

Removing the top/current element should stop playing. (This is probably a special case)