Hide ‘created at…’ on the templates page

I don’t think that if there’s only one version of the template that it’s
useful to see the created at date.

The auditing stuff only becomes relevant once someone a template has been
changed.

app/templates/components/email-message.html

@@ -7,7 +7,6 @@
   from_address=None,
   recipient=None,
   id=None,
-  created_at=None,
   updated_at=None,
   versions_url=None,
   version=1,
@@ -27,10 +26,6 @@
     {% if updated_at %}
       <p class="email-message-updated-at">Last updated on {{ updated_at|format_date_normal }} <a href="{{ versions_url }}">see earlier versions</a></p>
     {% endif %}
-  {% else %}
-    {% if created_at %}
-      <p class="email-message-updated-at">Created on {{ created_at|format_date_normal }}</p>
-    {% endif %}
   {% endif %}
   <div class="email-message">
     {% if from_name or subject %}