build: update gnulib submodule to latest

diff --git a/gnulib b/gnulib
index 6ab315e58df7718d4d4a307d415a5bb95b676654..32c16c45d7378b014d9aac6130104c4d02a9acdb 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 6ab315e58df7718d4d4a307d415a5bb95b676654
+Subproject commit 32c16c45d7378b014d9aac6130104c4d02a9acdb