title: Redirection not working on Safari and Firefox
body: <p>I'm using express-ntlm for authenticate my users on my app. For Mac OS, browsers ask for username and password and when a user insert a wrong password, it shows a page with a forbidden message. I overwrite <code>forbidden</code> function on my custom library so I can redirect users to the current URL so they can insert username and password again. For some reason this works on Chrome but not on Firefox or Safari, it just keep refreshing the page but doesn't prompt users for username and password. Looks like browser is storing the failed tried of log in and doesn't let you try again. </p>
  
  <pre><code>forbidden: function(req,res){
      res
        .status(401)
        .send(`&lt;!DOCTYPE html&gt;&lt;html&gt;&lt;head&gt;&lt;body&gt;
        &lt;h2&gt;Login failed, Please try again.&lt;/h2&gt;&lt;/body&gt;&lt;/head&gt;
        &lt;script&gt;
        window.setTimeout(function() {
          window.location.href = '${req.url}';
        }, 1000);
        &lt;/script&gt;&lt;/html&gt;`)
    }
  </code></pre>