build: update gnulib submodule to latest

diff --git a/gnulib b/gnulib
index bdd57f1ac8bb92dd8a44016709f07941b1301b69..be1e56a1b1845698830048a312e82f7a368af242 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit bdd57f1ac8bb92dd8a44016709f07941b1301b69
+Subproject commit be1e56a1b1845698830048a312e82f7a368af242