Update to newest gnulib.

diff --git a/gnulib b/gnulib
index d617a4bb9b2373961e2e605b78bd3dac346494be..a4398f60f17e3de5463540311bd6bc5c33045822 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit d617a4bb9b2373961e2e605b78bd3dac346494be
+Subproject commit a4398f60f17e3de5463540311bd6bc5c33045822