OpenSSL certificate should default to FQDN if possible.
Using IP addresses is not recommended, complicates dual stack
and limits addressing flexibility.
IPv6 control plane implementation [1] follow-up.
[1] Ia34e6916ea4f99e9522cd2ddde03a0a4776f7e2c
Change-Id: Ibfc02f933ddcc170e9d616d401e294ba0ff5e981