build: update gnulib submodule to latest

diff --git a/gnulib b/gnulib
index 2481e7a50d6535582856626b53009f419e2e05e2..a359f602d3e5a29f9381e70cc7e14a24a65e54ab 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 2481e7a50d6535582856626b53009f419e2e05e2
+Subproject commit a359f602d3e5a29f9381e70cc7e14a24a65e54ab