Avoid re-configuring (and validating) SSL/TLS configuration on `CONFIG
SET` when TLS is not actively enabled for incoming connections, cluster
bus or replication.
This fixes failures when tests run without `--tls` on binaries that were
built with TLS support.
An additional benefit is that it's now possible to perform a multi-step
configuration process while TLS is disabled. The new configuration will
be verified and applied only when TLS is effectively enabled.
(cherry picked from commit fb2a94af3fbb3f3cf8b26b8bd89387669cb111a1)
2e7ad58918