refactor: remove unused parameter in the Innertube constructor

lib/Innertube.js

@@ -13,7 +13,7 @@ const TimeToSeconds = require('time-to-seconds');
 const CancelToken = Axios.CancelToken;
 
 class Innertube extends EventEmitter {
-  constructor(cookie, sign_in) {
+  constructor(cookie) {
     super();
     this.cookie = cookie || '';
     return this.init();