Update to the newest gnulib.

diff --git a/gnulib b/gnulib
index 5d791c6bbcf2b31b35450bd5a57f45ca66cb532f..bdf8b1d2b74e12648edafffcda43832bc35e3d1f 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 5d791c6bbcf2b31b35450bd5a57f45ca66cb532f
+Subproject commit bdf8b1d2b74e12648edafffcda43832bc35e3d1f