refresh libusual

diff --git a/lib b/lib
index 031f6d73fa3f482aaf4ffc77e1d3f7d9f3fe7af5..55587de13d870b41878bb4c7c94139fe97cb7a96 160000 (submodule)
--- a/lib
+++ b/lib
@@ -1 +1 @@
-Subproject commit 031f6d73fa3f482aaf4ffc77e1d3f7d9f3fe7af5
+Subproject commit 55587de13d870b41878bb4c7c94139fe97cb7a96