swap method call in _switchFullScreen()

Author: bungcip

js/rpg_core/Graphics.js

@@ -1186,9 +1186,9 @@ Graphics._switchStretchMode = function() {
  */
 Graphics._switchFullScreen = function() {
     if (this._isFullScreen()) {
-        this._requestFullScreen();
-    } else {
         this._cancelFullScreen();
+    } else {
+        this._requestFullScreen();
     }
 };