fix: return early if keys is empty

src/database/redis/sets.js

@@ -19,6 +19,7 @@ module.exports = function (redisClient, module) {
 	module.setsAdd = function (keys, value, callback) {
 		callback = callback || function () {};
 		if (!Array.isArray(keys) || !keys.length) {
+			return setImmediate(callback);
 		}
 		helpers.execKeysValue(redisClient, 'batch', 'sadd', keys, value, function (err) {
 			callback(err);