Send actor in Undo Follow

src/remote/activitypub/renderer/undo.ts

@@ -1,4 +1,8 @@
-export default (object: any) => ({
+import config from '../../../config';
+import { ILocalUser, IUser } from "../../../models/user";
+
+export default (object: any, user: ILocalUser | IUser) => ({
 	type: 'Undo',
+	actor: `${config.url}/users/${user._id}`,
 	object
 });