update vkh

diff --git a/vkh b/vkh
index 18059c4c6464ff13ffb6764c8a882cf66d0676f5..0c9b7b9e6181a24673afcf4b87d850f405659308 160000 (submodule)
--- a/vkh
+++ b/vkh
@@ -1 +1 @@
-Subproject commit 18059c4c6464ff13ffb6764c8a882cf66d0676f5
+Subproject commit 0c9b7b9e6181a24673afcf4b87d850f405659308