ITS#8427 don't set tls_ctx if TLS wasn't requested

Also, set any remaining TLS options that weren't carried along
in the TLS ctx.
4 jobs for its8427b in 58 minutes and 43 seconds
Status Job ID Name Coverage
  Build
passed #1478
build-gnutls-mit

00:24:51

passed #1476
build-no-threads-no-slapd

00:03:40

passed #1483
build-openssl-heimdal

00:30:11

failed #1477
build-openssl-heimdal

00:28:39