unbound: update to 1.9.2 with package bug fixes

- fix package makefile resulted in resolved symlink and copied
double file contents of libunbound.so during install
- treat RFC6762 'local.' as nxdomain because avahi and other services
will disable if SOA or NS records appear in central DNS
- NLNetLabs has moved download and documentation sites

cherry-pick and squash from openwrt-19.07
add3e6c699
936a71739c
4618c74150

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

net/unbound/files/unbound.sh

@@ -1017,13 +1017,13 @@ unbound_hostname() {
 
     case "$UNBOUND_D_DOMAIN_TYPE" in
     deny|inform_deny|refuse|static)
-      {
-        # avoid upstream involvement in RFC6762 like responses (link only)
-        echo "  local-zone: local. $UNBOUND_D_DOMAIN_TYPE"
-        echo "  domain-insecure: local"
-        echo "  private-domain: local"
-        echo
-      } >> $UNBOUND_CONFFILE
+      if [ "$UNBOUND_TXT_DOMAIN" != "local" ] ; then
+        {
+          # avoid involvement in RFC6762, unless it is the local zone name
+          echo "  local-zone: local always_nxdomain"
+          echo
+        } >> $UNBOUND_CONFFILE
+      fi
       ;;
     esac