UI language menu links don't work in the nav bar

[joelit]

URL address of the page where you encountered the problem

Any Skosmos page!

Description of the problem

1. Choose a language from the nav bar
2. Get a Skosmos 'not found' error message
3. If your page URL was before localhost/Skosmos/something, it is now localhost/Skosmos/Skosmos/something
4. You can still write the correct URL for the chosen language yourself in the browser, though

Additional information (e.g. screenshots) about the problem

Skosmos/src/view/base-template.twig

Line 58 in 1e17ce9

<a class="fs-6 text-light ms-3 text-decoration-none" id="language-{{ langcode}}" href="{{ request.langurl(langcode) }}"> {{ langdata.name }}</a>

[osma]

This affects my local installation at http://localhost/Skosmos/ but not the demo installation at https://test.dev.finto.fi - presumably because the former has /Skosmos in the URL and the latter doesn't.

[osma]

Probably this has to do with setting the base URL.