Ticket 47637 - rsa_null_sha should not be enabled by default

Bug Description:  rsa_null_sha is enabled by default, this can allow unencrypted
                  traffic over a TLS connection.

Fix Description:  Disable rsa_null_sha, just like rsa_null_md5, by default.

https://fedorahosted.org/389/ticket/47637

Reviewed by: rmeggins(Thanks!)
(cherry picked from commit 82b12c97afd34ecc8acfe54baaf0f32bd83a7edf)