Failing unit test for ARQ collation with dockerized Fuseki

[osma]

URL address of the page where you encountered the problem

Not a URL, but the unit test for Jena ARQ collation is failing. It was therefore marked as skipped in PR #1496 but the problem remains.

Description of the problem

ARQ collation doesn't work in the Jena Fuseki Docker image. On the Jena side, this is tracked by apache/jena#1998 opened by @kinow .

Once the problem is fixed in Jena, we should:

1. copy the fix to Skosmos
2. reenable the unit test and make sure it passes