System info:
Linux Mint 18 (beta);
KDE Plasma Version: 5.6.5;
KDE Frameworks Version: 5.23.0;
Qt Version: 5.5.1;
Kernel Version: 4.4.0-36-generic
OS Type: 64-bit

In 'Connection editor' I am trying to add a vpn connection and the 'Connection type' should indicate "X.509 Certificates". However, unlike in previous versions, the drop-down menu does not offer this option. It only shows: Certificates (TLS), Static Key, Password, and Password with Certificates (TLS).
How can I add 'X.509 Certificates to the drop-down menu?
TIA