fix wrong port on frontend

frontend/src/RelayForm.tsx

@@ -8,7 +8,7 @@ type Assignment = {
   events: string[];
 };
 
-const backend = axios.create({ baseURL: "http://backend:1307" });
+const backend = axios.create({ baseURL: "http://backend:1308" });
 
 const RelayForm: React.FC = () => {
   const [forms, setForms] = useState<{ [key: string]: React.ReactNode }>({});