build: update gnulib submodule to latest

diff --git a/gnulib b/gnulib
index 8f8da7c809b6908d074ac64c91d0cedfd4236f2e..3b0ef0b854a43aea12364fafd4bb053d59c116f2 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 8f8da7c809b6908d074ac64c91d0cedfd4236f2e
+Subproject commit 3b0ef0b854a43aea12364fafd4bb053d59c116f2