Allow numbers in _getKey parameters

customize.dist/messages.js

@@ -93,7 +93,11 @@ define(req, function(Util, Default, Language) {
         var text = messages[key];
         if (typeof(text) === 'string') {
             return text.replace(/\{(\d+)\}/g, function (str, p1) {
-                return typeof(argArray[p1]) === 'string' ? argArray[p1] : '';
+                if (typeof(argArray[p1]) === 'string' || typeof(argArray[p1]) === "number") {
+                    return argArray[p1];
+                }
+                console.error("Only strings and numbers can be used in _getKey params!");
+                return '';
             });
         } else {
             return text;