build: update from gnulib

* gnulib: Update submodule to latest.

diff --git a/gnulib b/gnulib
index ee67d8ea6bd183f5ce32d90a6764705d766c3d6b..8a0efd04dc9583c96b4a0d3c311ff216e07dcdcd 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit ee67d8ea6bd183f5ce32d90a6764705d766c3d6b
+Subproject commit 8a0efd04dc9583c96b4a0d3c311ff216e07dcdcd