message: Update data.service.ts
  fix "Cannot GET /api//"
diff: @@ -218,7 +218,8 @@ export class UserDataService extends DataService {
  @Injectable()
  export class APIInfoService extends DataService {
  constructor(public backendService: BackendService) {
  - super('/', backendService);
  + // use root route
  + super('', backendService);
  }
  }
  