MFH (r295533): remove broken unbound-control-setup script

Approved by: re (glebius)
Relnotes: yes

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Build and install the Unbound caching DNS resolver daemon.

Approved by: re (blanket)