Update to newest gnulib.

diff --git a/gnulib b/gnulib
index 8089c00979a5b089cff592c6b91420e595657167..30f4fdcb53f803cb8308d34f3a51320812035c48 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 8089c00979a5b089cff592c6b91420e595657167
+Subproject commit 30f4fdcb53f803cb8308d34f3a51320812035c48