watermark: disable it when there's no watermark parameter on embed (close #124)
watermark: disable it when there's no watermark parameter on embed (close #124)

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