Add some bottom space between logout error and demo server message

[ci skip]

Signed-off-by: William Desportes <[email protected]>

Author: williamdes

templates/login/form.twig

@@ -1,7 +1,7 @@
 {{ login_header|raw }}
 
 {% if is_demo %}
-  <fieldset>
+  <fieldset class="mb-4">
     <legend>{% trans 'phpMyAdmin Demo Server' %}</legend>
     {% apply format('<a href="url.php?url=https://demo.phpmyadmin.net/" target="_blank" rel="noopener noreferrer">demo.phpmyadmin.net</a>')|raw %}
       {% trans %}