Redmine

I would like to check out Redmine source code, but subversion says that the server certificate is not trusted. I do not find anything about the certificate on www.redmine.org, including the fingerprint, so I cannot validate if this is valid or somebody is tampering with it. I guess it is good, because my browser does accept the certificate, when I open https://svn.redmine.org. But it would be better if the developers could confirm it.

# svn co https://svn.redmine.org/redmine/branches/3.4-stable redmine-3.4
Error validating server certificate for 'https://svn.redmine.org:443':
 - The certificate is not issued by a trusted authority. Use the
   fingerprint to validate the certificate manually!
Certificate information:
 - Hostname: svn.redmine.org
 - Valid: from Jan  8 00:00:00 2017 GMT until Jan  8 23:59:59 2020 GMT
 - Issuer: Gandi Standard SSL CA 2, Gandi, Paris, Paris, FR
 - Fingerprint: AB:F1:C8:B7:69:A6:99:BD:20:C1:59:A4:5F:60:9E:27:2D:81:82:B7
(R)eject, accept (t)emporarily or accept (p)ermanently? 

This is on Ubuntu 16.04.