Refresh libusual

diff --git a/lib b/lib
index 3aa3fc443c005ae98ac4ca3b5a4df5ff5c44222f..601a71a01f8e98b5b4f34fe6a8fbd8d1d1b21b04 160000 (submodule)
--- a/lib
+++ b/lib
@@ -1 +1 @@
-Subproject commit 3aa3fc443c005ae98ac4ca3b5a4df5ff5c44222f
+Subproject commit 601a71a01f8e98b5b4f34fe6a8fbd8d1d1b21b04