Update to the newest gnulib.

diff --git a/gnulib b/gnulib
index f4c40c2d6aabef8e587176bbf5226c8bc6649574..47548a77525a0f4489c9c420ccc2159079365da8 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit f4c40c2d6aabef8e587176bbf5226c8bc6649574
+Subproject commit 47548a77525a0f4489c9c420ccc2159079365da8