Update to the newest gnulib.

diff --git a/gnulib b/gnulib
index ea71051f3737fb5ad6d08b5c29211a70ceb50195..b5eb8780ffb06dbd633b667c1add43c8f7eb9b70 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit ea71051f3737fb5ad6d08b5c29211a70ceb50195
+Subproject commit b5eb8780ffb06dbd633b667c1add43c8f7eb9b70