[mailman3] Add info about disabled search

Signed-off-by: Michal Konecny <mkonecny@redhat.com>

roles/mailman3/files/base.html

@@ -84,6 +84,13 @@
                         {% endif %}
 
                 </div>
+                <ul class="nav navbar-nav order-2">
+                    <li class="nav-item" style="color:red">
+                        Search is temporarily disabled.
+                        See <a href="https://pagure.io/fedora-infrastructure/issue/12043">ticket</a> for more info.
+                    </li>
+                </ul>
+
 		<!--
                 <form name="search" method="get" action="{% url 'hk_search' %}" class="navbar-form navbar-right my-2 my-lg-2 order-1" role="search">
                     {% if mlist %}<input type="hidden" name="mlist" value="{{ mlist.name }}" />{% endif %}