refresh libusual

diff --git a/lib b/lib
index 7250ab4641689ff32853f198702c35b9f8609f56..610a5a9f0de5308e617e96910abf0aa3e453a83c 160000 (submodule)
--- a/lib
+++ b/lib
@@ -1 +1 @@
-Subproject commit 7250ab4641689ff32853f198702c35b9f8609f56
+Subproject commit 610a5a9f0de5308e617e96910abf0aa3e453a83c