Use EventEmitter.prototype.removeListener
Use EventEmitter.prototype.removeListener

instead of EventEmitter.prototype.off

Resolves #685

chhe/livestreamer-twitch-gui,chhe/livestreamer-twitch-gui,streamlink/streamlink-twitch-gui,streamlink/streamlink-twitch-gui,streamlink/streamlink-twitch-gui,chhe/livestreamer-twitch-gui