resolv.conf: Add "trust-ad" option

Since we are running unbound locally which always runs DNSSEC
validation, we can simply trust it and pass the ad flag on to
applications which make use of it.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>

src/initscripts/system/localnet

@@ -19,6 +19,7 @@ write_resolv_conf() {
 	(
 		[ -n "${DOMAINNAME}" ] && echo "search ${DOMAINNAME}"
 		echo "nameserver 127.0.0.1"
+		echo "options trust-ad"
 	) > /etc/resolv.conf
 }