MAGETWO-86506: Fix JS error on cart from postcode validation when 'US' is...

MAGETWO-86506: Fix JS error on cart from postcode validation when 'US' is deselected as an allowed country #13051

 - Merge Pull Request magento/magento2#13051 from codekipple/magento2:2.2-develop
 - Merged commits:
   1. c8ff538c