refactor(@angular-devkit/build-angular): remove basePort from check port

Close 8595

Author: tiaguinho

packages/angular_devkit/build_angular/src/angular-cli-files/utilities/check-port.ts

@@ -10,9 +10,8 @@ import { Observable } from 'rxjs';
 const portfinder = require('portfinder');
 
 
-export function checkPort(port: number, host: string, basePort = 49152): Observable<number> {
+export function checkPort(port: number, host: string): Observable<number> {
   return new Observable(obs => {
-    portfinder.basePort = basePort;
     // tslint:disable:no-any
     portfinder.getPort({ port, host }, (err: any, foundPort: number) => {
       if (err) {