Fix lint error by removing unused import
@@ -71,7 +71,7 @@ import 'zone.js/dist/zone'; // Included with Angular CLI.
// import 'rxjs/add/operator/combineLatest';
// import 'rxjs/add/operator/do';
// import 'rxjs/add/operator/filter';
-import 'rxjs/add/operator/first';
+// import 'rxjs/add/operator/first';
import 'rxjs/add/operator/map';
// import 'rxjs/add/operator/mergeMap';
// import 'rxjs/add/operator/share';
