Do not render page_title if it is empty

[nlhkabu]

In site_base.html we have the following code:

<h1>{% block page_title %}{% endblock %}</h1>

Sometimes page_title is empty and another h1 is defined later on the page.

In this case, we do not want to render the <h1> that wraps page_title.

In the short term I have issued a temporary fix, which hides the empty h1 with css.

However, this is not ideal, as the semantics of the page are messed up.

This is a suggested fix I found: https://chase-seibert.github.io/blog/2010/10/01/check-if-a-block-is-defined-in-django.html

There is also this https://github.com/edoburu/django-capture-tag