fix: usr: Rescan the interfaces again when reconfiguring the server

On FreeBSD, the server would not listen on the configured 'localhost'
interfaces immediately, but only after the 'interface-interval' period
has passed.  After the fix for default interface-interval was merged in
!10281, this means the server would listen on the localhost after 60
minutes.

Rescan the interfaces immediately after configuring the
interface-interval value to start listening on the 'localhost' interface
immediately.

Merge branch 'ondrej/rescan-the-interface-on-time-0' into 'bind-9.18'

See merge request isc-projects/bind9!10758