Merge pull request rpgtkoolmv#190 from rpgtkoolmv/fix_ua_change

Fix rendering stopped when changed user agent mobile safari to another.

Author: krmbn0576

js/rpg_managers/SceneManager.js

@@ -228,8 +228,9 @@ SceneManager.updateMain = function() {
         this.updateScene();
     } else {
         var newTime = this._getTimeInMsWithoutMobileSafari();
+        if (this._currentTime === undefined) { this._currentTime = newTime; }
         var fTime = (newTime - this._currentTime) / 1000;
-        if (fTime > 0.25) fTime = 0.25;
+        if (fTime > 0.25) { fTime = 0.25; }
         this._currentTime = newTime;
         this._accumulator += fTime;
         while (this._accumulator >= this._deltaTime) {