Logo path in Flex theme

Currently this site uses the pelican theme Flex, and I like it. But one thing annoyed me. There is a logo image on the left side and it works fine with the home, archive, and tag pages. But it does not show up on post pages. The reason is that the path to the logo image is set in pelicanconf.py and it seems to be relative URL from the current content which is dependent on the article. So setting

SITELOGO = "images/logo.png"

does not work for post pages. But I do not know how to set SITEURL into it.

So I modified directory pelican-themes/Flex/templates/base.html file, line 81, from

        {% if SITELOGO %}
        <img src="{{ SITELOGO }}" alt="{{ SITETITLE }}" title="{{ SITETITLE }}">
        {% else %}

to

        {% if SITELOGO %}
        <img src="{{ SITEURL }}/{{ SITELOGO }}" alt="{{ SITETITLE }}" title="{{ SITETITLE }}">
        {% else %}

I added {{ SITEURL }}/ before {{ SITELOGO }} to make the SITELOGO path as a relative path from SITEURL.

Then it works fine even at post pages.

But after struggling on this for hours, it turns out that just setting

SITELOGO = "/images/logo.png"

solves the issue here… What a waste of time…