Update gnulib

diff --git a/gnulib b/gnulib
index 6f9206d4db914cf904cd4711e3044d99c36dae8b..68b6adebef05670a312fb92b05e7bd089d2ed43a 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 6f9206d4db914cf904cd4711e3044d99c36dae8b
+Subproject commit 68b6adebef05670a312fb92b05e7bd089d2ed43a