refresh libusual

diff --git a/lib b/lib
index 84b8105578a282d34ff417022ba5cd52adba7996..e4a86f4af27f958cdf8a6dcb08954ae6c745be6f 160000 (submodule)
--- a/lib
+++ b/lib
@@ -1 +1 @@
-Subproject commit 84b8105578a282d34ff417022ba5cd52adba7996
+Subproject commit e4a86f4af27f958cdf8a6dcb08954ae6c745be6f