Update to the newest gnulib.

diff --git a/gnulib b/gnulib
index 93b78ec081ff9e5be8f4cdcc44dd4f6f5da15164..4d38340a76dbee56036a5fcc0f052ebcff616a59 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 93b78ec081ff9e5be8f4cdcc44dd4f6f5da15164
+Subproject commit 4d38340a76dbee56036a5fcc0f052ebcff616a59