c'est safe j'ai verifié le code d'ailleur le voici


// ==UserScript==
// @name ISSOU YATANGAKI 502 GATEWAY FIXER
// @description Refresh on failed page loading & Gateway problems, '502 Bad Gateway','504 Gateway Time-out', 'Problem loading page', '503 Service Temporarily Unavailable', '500 Internal Server Error', 'Error 503 Service Unavailable', '404 Not Found', '504 Gateway Time-out'
// @author MARILYNMANSON
// @namespace
// @version 1
// @updateURL
// @include *
// @grant none
// ==/UserScript==

var time = 1;

(function ()
{
if (document.title == '502 Bad Gateway' )
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.title == '504 Gateway Time-out' )
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.title == 'Problem loading page' )
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.title == '503 Service Temporarily Unavailable' )
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.title == 'Service Unavailable' )
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.title == '500 Internal Server Error' )
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.title == 'Database error' )
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.title == 'FastCGI Error' )
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.title == 'The connection has timed out' )
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.title == 'Problemas al cargar la página' )
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.title == 'Error 502 (Server Error)!!1' )
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.getElementsByTagName('h1')[0].innerHTML == '502 Bad Gateway')
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.getElementsByTagName('h1')[0].innerHTML == 'Service Unavailable')
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.getElementsByTagName('h1')[0].innerHTML == 'Error 503 Service Unavailable')
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.getElementsByTagName('h1')[0].innerHTML == '404 Not Found')
{setTimeout(function() {window.location.reload(true);}, time);}
else if (document.getElementsByTagName('h1')[0].innerHTML == '504 Gateway Time-out')
{setTimeout(function() {window.location.reload(true);}, time);}
})();