Update to the newest gnulib.

diff --git a/gnulib b/gnulib
index dc1b410b9ab160fb51f316bdc32def98499d1b17..66f9edfa59dc1ae55a189fb9b647b7319b2a1b02 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit dc1b410b9ab160fb51f316bdc32def98499d1b17
+Subproject commit 66f9edfa59dc1ae55a189fb9b647b7319b2a1b02