MAGETWO-81991: Checkout page could hang for Javascript error #10975

 - Merge Pull Request #10975 from angelo983/magento2:2.1-develop
 - Merged commits:
   1. 60f47fc

Author: Oleksii Korshenko

lib/web/mage/utils/arrays.js

@@ -101,7 +101,7 @@ define([
                 newIndex,
                 target;
 
-            if (typeof position === 'undefined') {
+            if (typeof position === 'undefined' || position == null) {
                 position = -1;
             } else if (typeof position === 'string') {
                 position = isNaN(+position) ? position : +position;