Update SG postal code validator to reflect correctly.

src/js/validator/zipCode.js

@@ -44,8 +44,8 @@
                 case 'NL': return /^[1-9][0-9]{3} ?(?!sa|sd|ss)[a-z]{2}$/i.test(value);
 
                 case 'SE': return /^(S-)?\d{3}\s?\d{2}$/i.test(value);
-                case 'US':
                 case 'SG': return /^([0][1-9]|[1-6][0-9]|[7]([0-3]|[5-9])|[8][0-2])(\d{4})$/i.test(value);
+                case 'US':
                 default: return /^\d{4,5}([\-]\d{4})?$/.test(value);
             }
         },