gluon-core: add interfaces having proto = gluon_mesh to mesh firewall zone

Based-on-patch-by: Christof Schulze <christof.schulze@gmx.net>

package/gluon-core/files/lib/netifd/proto/gluon_mesh.sh

@@ -28,6 +28,7 @@ proto_gluon_mesh_setup() {
 	proto_add_data
 	json_add_boolean fixed_mtu "$FIXED_MTU"
 	json_add_boolean transitive "$TRANSITIVE"
+	[ "$IFNAME" != 'br-wan' ] && json_add_string zone 'mesh'
 	proto_close_data
 	proto_send_update "$CONFIG"