Update base.j2 to make server messages <h2>.

Signed-off-by: Ari Archer <ari@ari.lt>

src/templates/base.j2

@@ -42,7 +42,7 @@
         <details open>
         <summary>messages from the server</summary>
         {% for category, message in messages %}
-        <div><b>[{{ category | escape }}] {{ message | escape }}</b></div>
+        <h2>[{{ category | escape }}] {{ message | escape }}</h2>
         {% endfor %}
         </details>
         {% endif %}