Add host prefix to template download in test rules page

Author: Christoffer-Cortes

src/main/resources/static/js/testrules.js

@@ -342,7 +342,7 @@ jQuery(document).ready(
 
       function getTemplate(name) {
         var request = new XMLHttpRequest();
-        request.open("GET", '/download/' + name, true);
+        request.open("GET", frontendServiceUrl + '/download/' + name, true);
         request.responseType = "application/json;charset=utf-8";
         request.onload = function (event) {
            var jsonData = JSON.stringify(JSON.parse(request.response), null, 2);