To set xCALLY in the https secure connection go to the Settings -> General -> Secure Connection and select Yes.
After this change you have to reset the xcally-realtime service, using the command service xcally-realtime restart.
When you access to the xCALLY URL for the first time, you have also to accept the website certificate.
Open the linux console on your xcally server and edit the file: /etc/asterisk/res_xcalld.conf
Reload the Asterisk configuration, type: asterisk –rx “reload”