Fix missing scheme in API url

frontend/allowance-planner-v2/src/app/services/user.service.ts

@@ -7,7 +7,7 @@ import { User } from '../models/user';
     providedIn: 'root',
 })
 export class UserService {
-    private url = 'localhost:59772/api';
+    private url = 'http://localhost:8080/api';
     constructor(private http: HttpClient) {}
 
     getUserList(): Observable<Array<User>> {
@@ -17,4 +17,4 @@ export class UserService {
     getUserById(id: number): Observable<User> {
         return this.http.get<User>(`${this.url}/user/${id}`);
     }
-}
+}