Check zonefile is untouched if dnssec-policy none

Make sure no DNSSEC contents are added to the zonefile if dnssec-policy
is set to "none" (and no .state files exist for the zone).

(cherry picked from commit 5246c16f43e6fda7587193a4dd801951cf87db14)

bin/tests/system/kasp/ns3/setup.sh

@@ -77,6 +77,7 @@ zone="unsigned.kasp"
 echo_i "setting up zone: $zone"
 zonefile="${zone}.db"
 infile="${zone}.db.infile"
+cp template.db.in $infile
 cp template.db.in $zonefile
 
 # Set up zone that stays unsigned.

bin/tests/system/kasp/tests.sh

@@ -805,6 +805,13 @@ check_keys
 check_dnssecstatus "$SERVER" "$POLICY" "$ZONE"
 check_apex
 check_subdomain
+# Make sure the zone file is untouched.
+n=$((n+1))
+echo_i "Make sure the zonefile for zone ${ZONE} is not edited ($n)"
+ret=0
+diff "${DIR}/${ZONE}.db.infile" "${DIR}/${ZONE}.db" || ret=1
+test "$ret" -eq 0 || echo_i "failed"
+status=$((status+ret))
 
 #
 # Zone: insecure.kasp.