build: update gnulib to latest

diff --git a/gnulib b/gnulib
index 001a31578623e5bffceb5845cddaad46a9c9505d..acff3d22506764c18129317d2a8beb4af27ee28e 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 001a31578623e5bffceb5845cddaad46a9c9505d
+Subproject commit acff3d22506764c18129317d2a8beb4af27ee28e