playlist/fetcher: interrupt fetcher thread on exit
playlist/fetcher: interrupt fetcher thread on exit

This unblocks playlist_fetcher_Delete if a task is blocked on I/O.

This doesn't prevent a task to block all next tasks on a normal run.

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc