This problem still persists to this day. Setting system-ca-certs=false does not work, you have to comment it out or remove it. There needs to be an option in network manager UI to allow users to disable the requirement on system-ca-cert and it should be included in the dialogue that prompts you for a ca along with the "Don't remind me again" or "ignore this" (e.g. setting it to ignore should unset or remove that line from the connection configuration.
This problem still persists to this day. Setting system- ca-certs= false does not work, you have to comment it out or remove it. There needs to be an option in network manager UI to allow users to disable the requirement on system-ca-cert and it should be included in the dialogue that prompts you for a ca along with the "Don't remind me again" or "ignore this" (e.g. setting it to ignore should unset or remove that line from the connection configuration.