Refresh libusual

diff --git a/lib b/lib
index 601a71a01f8e98b5b4f34fe6a8fbd8d1d1b21b04..1acff787e7197ab91d7a7e50d50243fc2a8d0625 160000 (submodule)
--- a/lib
+++ b/lib
@@ -1 +1 @@
-Subproject commit 601a71a01f8e98b5b4f34fe6a8fbd8d1d1b21b04
+Subproject commit 1acff787e7197ab91d7a7e50d50243fc2a8d0625