ui: remove outdated csrfToken field

packages/ui-default/templates/user_logout.html

@@ -4,7 +4,6 @@
   <div class="immersive--content immersive--center">
     <h1>{{ _('Logout') }}</h1>
     <form method="POST">
-      <input type="hidden" name="csrfToken" value="{{ handler.csrfToken }}">
       <div class="text-center">
         <input type="submit" value="{{ _('Logout') }}" class="inverse rounded primary button">
       </div>