sso 7.4 only available on RHEL 8

All RHEL 8 images require authentication and the latest version of sso is 7.4.  Unfortunately, this version is only available on RHEL 8, so for now the secured examples will continue to use 7.3 as it's still available on RHEL 7 without an authentication requirement.  A longer term solution needs to be determined for this situation.