Update to the newest gnulib.

diff --git a/gnulib b/gnulib
index 588b8d0c0cfe366c4fa24a367767b385edb62fec..2529243503f93aed2ddb249e4b459c5afda78add 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 588b8d0c0cfe366c4fa24a367767b385edb62fec
+Subproject commit 2529243503f93aed2ddb249e4b459c5afda78add