Update gnulib

diff --git a/gnulib b/gnulib
index a6aa0b6f74864a94e940b310f6200e18f7d9dcc9..5d1b1fefb1998e0ec59dba3bc1be1993e4eb6be3 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit a6aa0b6f74864a94e940b310f6200e18f7d9dcc9
+Subproject commit 5d1b1fefb1998e0ec59dba3bc1be1993e4eb6be3