hls playback: make all calls to external interfaces safe
hls playback: make all calls to external interfaces safe

Conflicts:
	src/plugins/hls_playback/hls_playback.js

Pyrotoxin/clappr,clappr/clappr,dayvson/clappr,MariadeAnton/clappr,shakin/clappr,flavioribeiro/clappr,jfairley/clappr,Pyrotoxin/clappr,Pyrotoxin/clappr,shakin/clappr,flavioribeiro/clappr,dayvson/clappr,leandromoreira/clappr,dayvson/clappr,kelonye/clappr,kelonye/clappr,Peer5/clappr,tjenkinson/clappr,jfairley/clappr,Metrakit/clappr,kelonye/clappr,tjenkinson/clappr,MariadeAnton/clappr,shakin/clappr,tjenkinson/clappr,clappr/clappr,wxmfront/clappr,Peer5/clappr,clappr/clappr,wxmfront/clappr,Metrakit/clappr,tarkanlar/clappr,Metrakit/clappr,Peer5/clappr,tarkanlar/clappr,leandromoreira/clappr,burakkp/clappr,burakkp/clappr,burakkp/clappr,leandromoreira/clappr,flavioribeiro/clappr,MariadeAnton/clappr,irongomme/clappr,tarkanlar/clappr,irongomme/clappr,irongomme/clappr,jfairley/clappr,wxmfront/clappr