Merge pull request phaserjs#4151 from Waclaw-I/HTML5AudioSound-fixes

Setting HTML5AudioSound's volume and mute is now working.

Author: photonstorm

src/sound/html5/HTML5AudioSound.js

@@ -634,6 +634,7 @@ var HTML5AudioSound = new Class({
             {
                 return;
             }
+            this.updateMute();
 
             this.emit('mute', this, value);
         }
@@ -686,6 +687,7 @@ var HTML5AudioSound = new Class({
             {
                 return;
             }
+            this.updateVolume();
 
             this.emit('volume', this, value);
         }