deblayout: Add missing close tags for <div id="content"> and messages

The #content div must be closed before the #footer div is opened. For
the messages, there is an opening <div>, but a closing </li>. I assume
that the </li> should be a </div>, as there is no <ul> or <ol> around
the list.

Signed-off-by: Julian Andres Klode <jak@debian.org>

deblayout/templates/debian-base.html

@@ -99,7 +99,7 @@ Always leave one space between the slash and the link.
 
 {% if messages %}
 {% for message in messages %}
-<div class="{% if message.tags %}{{ message.tags }}{% else %}important{% endif %}"><p>{{ message }}</p></li>
+<div class="{% if message.tags %}{{ message.tags }}{% else %}important{% endif %}"><p>{{ message }}</p></div>
 {% endfor %}
 {% endif %}
 
@@ -110,6 +110,7 @@ Always leave one space between the slash and the link.
 	-->
 	Debian Website Template</h1>
 {% endblock %}
+</div>
 
 <div id="footer">
 {% block footer %}