Update to the newest gnulib.

diff --git a/gnulib b/gnulib
index 7ded27a6c89101fce7f00203b3439f8d40f281b4..661c55d6c287e1e6122e0ec03668ec859b6d806a 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 7ded27a6c89101fce7f00203b3439f8d40f281b4
+Subproject commit 661c55d6c287e1e6122e0ec03668ec859b6d806a