Update libusual

diff --git a/lib b/lib
index b3b239063d054cfdc6ea1f3602de92c90bdc8977..6cc69da7beed13259094ee976bcc2d57c5edbf2e 160000 (submodule)
--- a/lib
+++ b/lib
@@ -1 +1 @@
-Subproject commit b3b239063d054cfdc6ea1f3602de92c90bdc8977
+Subproject commit 6cc69da7beed13259094ee976bcc2d57c5edbf2e