Update interface.

diff --git a/interface b/interface
index f778e84b6fd836e200be868fcaeaf73bc3bf496b..4f7e7b639bdc131a4c008f447bc03cc49d51fbd9 160000 (submodule)
--- a/interface
+++ b/interface
@@ -1 +1 @@
-Subproject commit f778e84b6fd836e200be868fcaeaf73bc3bf496b
+Subproject commit 4f7e7b639bdc131a4c008f447bc03cc49d51fbd9