Package: wiki.x2go.org

While checking URLs with LWP/curl, I noticed that wiki.x2go.org fails:

| [tim@passepartout ~]$ curl https://wiki.x2go.org/ | curl: (60) SSL certificate problem: unable to get local issuer certificate | More details here: https://curl.haxx.se/docs/sslcerts.html

| curl failed to verify the legitimacy of the server and therefore could not | establish a secure connection to it. To learn more about this situation and | how to fix it, please visit the web page mentioned above. | [tim@passepartout ~]$

Staring at "openssl s_client -connect wiki.x2go.org:443", https://www.ssllabs.com/ssltest/analyze.html?d=wiki.x2go.org and https://letsencrypt.org/certificates/ suggests to a layman that the server certificate is signed by the R3 certificate, but the X3 certificate is sent along?