0022821: Hide any text parameter from Trusted Networks

Migrated from: https://tracker.clearos.com/view.php?id=22821

Reported by: NHowitt

Currently the Trusted Networks does not display the "mynetworks" values of 127.0.0.0/8 and [::1]/128. Please can that be extended do not display any text value or value beginning $.

The justification for this is that ClearGLASS was adding 172.16/12 to mynetworks as a sledgehammer to get round not knowing which subnet ClearGLASS was using in docker. Clearglass-community has now been updated to maintain the variable $clearglassnetwork in /etc/postfix/main.cf under program control so it should not be displayed in the Webconfig as one of the Trusted Networks.