How to fix SSL error 61 in Citrix Web Receiver on Linux

How to fix SSL error 61 in Citrix on LinuxI admit, the title is quite specific and will certainly appeal to only a small readership. But anyone who is facing the problem will be, like me, grateful for a solution.
In particular, the problem is about the SSL error 61 in the Citrix (Web) receiver under Linux and how to fix it. Since I have been running almost exclusively under Kubuntu for several months, the Citrix Reiceiver also moved into the new Linux box. Unfortunately, no connection to systems could be established, since the receiver disconnected with the following error message.
SSL Error 61: You have not chosen to trust “Go Daddy Root Certificate Authority – G2”, the issuer to the server’s security certificate.
Citrix-SSL-Fehler-61What […]