Fix datatable for list fo sign-up domains

core/admin/mailu/ui/templates/user/signup_domain.html

@@ -10,11 +10,14 @@
 
 {%- block content %}
 {%- call macros.table(order='[[1,"asc"]]') %}
-<tr>
+<thead>
+  <tr>
     <th>{% trans %}Domain{% endtrans %}</th>
     <th>{% trans %}Available slots{% endtrans %}</th>
     <th>{% trans %}Quota{% endtrans %}</th>
-</tr>
+  </tr>
+</thead>
+<tbody>
 {%- for domain_name, domain in available_domains.items() %}
 <tr>
   <td><a href="{{ url_for('.user_signup', domain_name=domain_name) }}">{{ domain_name }}</a></td>
@@ -22,5 +25,6 @@
   <td data-ordered="{{ domain.max_quota_bytes or config['DEFAULT_QUOTA'] }}">{{ domain.max_quota_bytes or config['DEFAULT_QUOTA'] | filesizeformat }}</td>
 </tr>
 {%- endfor %}
+</tbody>
 {%- endcall %}
 {%- endblock %}