gluon-radvd: run on local-node instead of br-client

On a layer 3 mesh, we'd like the default route to point to all node's
local-node interface for roaming to work.

package/gluon-radvd/files/etc/init.d/gluon-radvd

@@ -7,7 +7,7 @@ SERVICE_DAEMONIZE=1
 
 
 start() {
-	service_start /usr/sbin/uradvd -i br-client -p $(lua -e 'print(require("gluon.site_config").prefix6)')
+	service_start /usr/sbin/uradvd -i local-node -a $(lua -e 'print(require("gluon.site_config").prefix6)')
 }
 
 stop() {