build: update with gnulib fixes

* gnulib: Update to incorporate gnulib fixes
from Bruno Haible from his coreutils 9.4 pre-release testing.

diff --git a/gnulib b/gnulib
index c5a5f46e54ce045b5c67cf3258f2c344b40bdbdc..bb5bb43a1ebb9f502b5ce38c0b8c8778d13b9f6e 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit c5a5f46e54ce045b5c67cf3258f2c344b40bdbdc
+Subproject commit bb5bb43a1ebb9f502b5ce38c0b8c8778d13b9f6e