Refresh libusual to pick up Antimake fixes

diff --git a/lib b/lib
index 2f5400f2d6ae782da5f5522ad46dc3ede672e4ca..3aa3fc443c005ae98ac4ca3b5a4df5ff5c44222f 160000 (submodule)
--- a/lib
+++ b/lib
@@ -1 +1 @@
-Subproject commit 2f5400f2d6ae782da5f5522ad46dc3ede672e4ca
+Subproject commit 3aa3fc443c005ae98ac4ca3b5a4df5ff5c44222f