Maintain old Reddit without old.reddit.com redirect

reddit.js

// ==UserScript==
// @name         Maintain old Reddit without old.reddit.com redirect
// @namespace    https://github.com/fukionline
// @version      1.0.0
// @description  
// @author       fukionline
// @match        *://*.reddit.com/*
// @grant        GM_addStyle
// @grant        GM_setValue
// @grant        GM_getValue
// @grant        GM_xmlhttpRequest
// @grant        GM_registerMenuCommand
// @license      WTFPL
// @downloadURL https://gist.github.com/fukionline/7a9c1294b4948bdac649abc6f64534b5/raw/56c4e5a2fa61f043f7cbb75cadb291e3aba3607a/reddit.js
// @updateURL https://gist.github.com/fukionline/7a9c1294b4948bdac649abc6f64534b5/raw/56c4e5a2fa61f043f7cbb75cadb291e3aba3607a/reddit.js
// ==/UserScript==

(function () {
    'use strict';
    function setCookie(name, value, days, domain) {
        let expires = "";
        if (days) {
            const date = new Date();
            date.setTime(date.getTime() + (days*24*60*60*1000));
            expires = "; expires=" + date.toUTCString();
        }
        document.cookie = name + "=" + encodeURIComponent(value) + expires + "; path=/; domain=" + domain + "; Secure; SameSite=None";
    }

    // Check for old Reddit and set pro-Old reddit cookies if necessary
    const cookies = document.cookie.split("; ").reduce((acc, c) => {
        const [key, val] = c.split("=");
        acc[key] = val;
        return acc;
    }, {});

    if (cookies["theme"] !== "1") {
        setCookie("theme", "1", 365, ".reddit.com");
    }

    if (cookies["redesign_optout"] !== "true") {
        setCookie("redesign_optout", "true", 365, ".reddit.com");
    }    
})();