refresh libusual

diff --git a/lib b/lib
index 363ffc1a84d30ce5b90e27b4fa522cd9c4a336ef..870fb4dc563d44a1b73f49b0644147fd2b0bec26 160000 (submodule)
--- a/lib
+++ b/lib
@@ -1 +1 @@
-Subproject commit 363ffc1a84d30ce5b90e27b4fa522cd9c4a336ef
+Subproject commit 870fb4dc563d44a1b73f49b0644147fd2b0bec26