Fix wrong filename

src/frontend/assets/js/app.js

@@ -20,7 +20,7 @@ const callApi = (url, callback) => {
         });
 };
 
-callApi('/public-config', data => {
+callApi('/public-config.json', data => {
     const BASE_URL = "http://" + data.backend_ip_address + "/api/v1";
 
     callApi(BASE_URL + '/cv/summary', data => {