unbound: bugfix init race condition invalid FQDN

unbound: bugfix init race condition invalid FQDN

options 'add_local_fqdn' and 'add_wan_fqdn' can be affected
by race conditions when they are at level 4. Interface name
may not be returned by network tools. The conf file has bad
record formats and Unbound just will not load. Detect this
and fall back to only the host FQDN (level 3).

squash: improve documentation wording and format codes.

Signed-off-by: Eric Luehrsen <ericluehrsen@hotmail.com>