kaiju-makedb: Mar DB fails

[pmenzel]

The download of Mar metadata fails at

Downloading MarRef metadata from MMP (databasesapi.sfb.uit.no)

I think it's a problem with the line

 MARREF_VERSION=$(curl -Ls -o /dev/null -w %{url_effective} https://databasesapi.sfb.uit.no/rest/v1/MarRef/records | grep -Po 'ver=\K\d+\.\d+')     

@emrobe