Fix auto-certification with unknown licence
Fix auto-certification with unknown licence

Auto-certification fails with an unknown licence abbreviation. Valid
values for `dataLicence` are only known licences and nil.

Motejl/open-data-certificate,zoul/open-data-certificate,theodi/open-data-certificate,zoul/open-data-certificate,zoul/open-data-certificate,theodi/open-data-certificate,ahmadassaf/open-data-certificate,Motejl/open-data-certificate,ahmadassaf/open-data-certificate,theodi/open-data-certificate,ahmadassaf/open-data-certificate,ahmadassaf/open-data-certificate,zoul/open-data-certificate,Motejl/open-data-certificate,Motejl/open-data-certificate,theodi/open-data-certificate