fix: use simpler getSortedSetRevRange instead of unnecessary zunion call

/cc @barisusakli

src/activitypub/index.js

@@ -2,7 +2,6 @@
 
 const nconf = require('nconf');
 const { createHash, createSign, createVerify } = require('crypto');
-const validator = require('validator');
 
 const request = require('../request');
 const db = require('../database');

src/user/follow.js

@@ -73,14 +73,10 @@ module.exports = function (User) {
 		if (parseInt(uid, 10) <= 0) {
 			return [];
 		}
-		const uids = await db.getSortedSetRevUnion({
-			sets: [
+		const uids = await db.getSortedSetRevRange([
 			`${type}:${uid}`,
 			`${type}Remote:${uid}`,
-			],
-			start,
-			stop,
-		});
+		], start, stop);
 
 		const data = await plugins.hooks.fire(`filter:user.${type}`, {
 			uids: uids,