Fix mlr test with solution that works for CentOS too

[valeriupredoi]

sorry Manu man @schlunma - this fell through the cracks for a long time 🍺

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Closes #1890

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[schlunma]

Cheers V., great stuff! Code looks fine and the tests works on my local machine and on the CI machine 👍 Thanks!

[valeriupredoi]

gut gut, it's your code so if it didn't look fine I would have pointed straight at you 😁