imporved env check

Author: dinodsaurus

lib/helpers/ariaAppHider.js

@@ -1,7 +1,4 @@
-var _element = "";
-if(typeof window !== 'undefined'){
-  _element = document.body;
-}
+var _element = typeof document !== 'undefined' ? document.body : null;
 
 function setElement(element) {
   if (typeof element === 'string') {