Update to newest gnulib.

diff --git a/gnulib b/gnulib
index 4cfff6810c595e60cf4411dc9bac83c0328e8812..3f53c355dd2efa18317f53d24c8b19b8a278674f 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 4cfff6810c595e60cf4411dc9bac83c0328e8812
+Subproject commit 3f53c355dd2efa18317f53d24c8b19b8a278674f