build: update gnulib submodule to latest

diff --git a/gnulib b/gnulib
index 4e944641037342d36f31547bec6a73ca910d5bd9..d08b322eb976bb974ff3fa9542064ff7973f632a 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 4e944641037342d36f31547bec6a73ca910d5bd9
+Subproject commit d08b322eb976bb974ff3fa9542064ff7973f632a