Sync libusual

diff --git a/lib b/lib
index 2f0d8767f2b0ca3f4aacd46cde1fc93019a2ae70..ab4f9b547919a22c32ef9e2c7e3925c374b17ecf 160000 (submodule)
--- a/lib
+++ b/lib
@@ -1 +1 @@
-Subproject commit 2f0d8767f2b0ca3f4aacd46cde1fc93019a2ae70
+Subproject commit ab4f9b547919a22c32ef9e2c7e3925c374b17ecf