Use WHATWG API

> New application code should use the WHATWG API.

src/remote/webfinger.ts

@@ -1,6 +1,5 @@
 import config from '../config';
 import * as request from 'request-promise-native';
-import { URL } from 'url';
 import { query as urlQuery } from '../prelude/url';
 
 type ILink = {