Couple GELI swap with GELI root option in bsdinstall zfsboot.
If you haven't touched the GELI swap option, toggling GELI root
to enabled will automatically toggle GELI swap to enabled.
Similarly, if you toggle GELI root off, GELI swap will also be
disabled at the same time (again, only if you haven't touched
the GELI swap option, which would indicate you have a preference
for either Encrypted or Unencrypted swap).

MFC after: 3 days
X-MFC-to: stable/10