build: update gnulib submodule to latest

diff --git a/gnulib b/gnulib
index 73e6357e410c70a12ebedac4fc9d48f97e2c0ad4..bdd57f1ac8bb92dd8a44016709f07941b1301b69 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 73e6357e410c70a12ebedac4fc9d48f97e2c0ad4
+Subproject commit bdd57f1ac8bb92dd8a44016709f07941b1301b69