Removed touchstart event listeners since they don't work for unlocking audio

Author: pavle-goloskokovic

src/sound/html5/HTML5AudioSoundManager.js

@@ -75,7 +75,6 @@ var HTML5AudioSoundManager = new Class({
         var _this = this;
         if ('ontouchstart' in window) {
             var unlock_1 = function () {
-                document.body.removeEventListener('touchstart', unlock_1);
                 document.body.removeEventListener('touchend', unlock_1);
                 _this.game.cache.audio.entries.each(function (key, tags) {
                     for (var i = 0; i < tags.length; i++) {
@@ -84,7 +83,6 @@ var HTML5AudioSoundManager = new Class({
                     return true;
                 });
             };
-            document.body.addEventListener('touchstart', unlock_1, false);
             document.body.addEventListener('touchend', unlock_1, false);
         }
     },