audio: Workaround a bug in Opera
audio: Workaround a bug in Opera

- See: https://github.com/goldfire/howler.js/issues/328

gopalindians/melonJS,melonjs/melonJS,TukekeSoft/melonJS,gopalindians/melonJS,melonjs/melonJS,rlugojr/melonJS,gopalindians/melonJS,srbala/melonJS,TukekeSoft/melonJS,rlugojr/melonJS,srbala/melonJS,rlugojr/melonJS,srbala/melonJS,TukekeSoft/melonJS