stream.hls: Some minor improvements.
stream.hls: Some minor improvements.

chrippa/livestreamer,fishscene/streamlink,hmit/livestreamer,mmetak/streamlink,ethanhlc/streamlink,derrod/livestreamer,flijloku/livestreamer,javiercantero/streamlink,sbstp/streamlink,chrippa/livestreamer,programming086/livestreamer,asermax/livestreamer,bastimeyer/streamlink,ethanhlc/streamlink,bastimeyer/streamlink,charmander/livestreamer,melmorabity/streamlink,Masaz-/livestreamer,Dobatymo/livestreamer,chrisnicholls/livestreamer,derrod/livestreamer,wlerin/streamlink,okaywit/livestreamer,gtmanfred/livestreamer,back-to/streamlink,blxd/livestreamer,okaywit/livestreamer,streamlink/streamlink,Klaudit/livestreamer,flijloku/livestreamer,Masaz-/livestreamer,fishscene/streamlink,breunigs/livestreamer,sbstp/streamlink,Feverqwe/livestreamer,mmetak/streamlink,wolftankk/livestreamer,Saturn/livestreamer,lyhiving/livestreamer,caorong/livestreamer,breunigs/livestreamer,gravyboat/streamlink,Saturn/livestreamer,jtsymon/livestreamer,intact/livestreamer,wolftankk/livestreamer,streamlink/streamlink,Feverqwe/livestreamer,javiercantero/streamlink,programming086/livestreamer,chhe/streamlink,chhe/livestreamer,Dobatymo/livestreamer,Klaudit/livestreamer,charmander/livestreamer,caorong/livestreamer,hmit/livestreamer,chhe/streamlink,beardypig/streamlink,jtsymon/livestreamer,gtmanfred/livestreamer,blxd/livestreamer,beardypig/streamlink,gravyboat/streamlink,melmorabity/streamlink,back-to/streamlink,chhe/livestreamer,wlerin/streamlink,lyhiving/livestreamer,intact/livestreamer