Update to the newest gnulib.

diff --git a/gnulib b/gnulib
index b00a9678886a17c60355454e59c71d32b9b8f789..f3967bd90989306a8802f00d0b1aa1811f0c1b96 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit b00a9678886a17c60355454e59c71d32b9b8f789
+Subproject commit f3967bd90989306a8802f00d0b1aa1811f0c1b96