          <div class="page-header-inner">
            <div class="row row--space-between row--vertically-centered">
              <div class="column-auto">
                <a href="/" class="brand-logo"><span>CozyLAN</span></a>
              </div>
              <div class="column-auto column-auto--grow">
                <span class="brand-slogan">Gemütlich zocken.</span>
              </div>
              <div class="column-auto">
{%- include 'layout/_locale_selector.html' %}
              </div>
              <div class="column-auto">
{%- include 'layout/_current_user.html' %}
              </div>
            </div>
          </div>

          <div class="page-header-inner">
            <div class="row row--space-between row--vertically-centered">
              <div class="column-auto">
                <a href="/" class="brand-logo"><span>CozyLAN</span></a>
              </div>
              <div class="column-auto column-auto--grow">
                <span class="brand-slogan">Gemütlich zocken.</span>
              </div>
              {%- if not g.user.locale %}
              <div class="column-auto">
{%- include 'layout/_locale_selector.html' %}
              </div>
              {%- endif %}
              <div class="column-auto">
{%- include 'layout/_current_user.html' %}
              </div>
            </div>
          </div>

Hide CozyLAN locale selector if user is logged in
Hide CozyLAN locale selector if user is logged in

This is a debatable move, but for now it avoids confusion in so far as
that a change with that dropdown does not have an effect as the current
user will have a locale set.
