message: chore(ConnectableObservable): remove unused code
  there is no need for the assignment
diff: @@ -45,8 +45,6 @@ export class ConnectableObservable<T> extends Observable<T> {
  if (connection.closed) {
  this._connection = null;
  connection = Subscription.EMPTY;
  - } else {
  - this._connection = connection;
  }
  }
  return connection;
  