build: update gnulib submodule to latest

diff --git a/gnulib b/gnulib
index 2f52828cd17068135575bc2bd84e2afebae5e214..0ac98783691bbf8212537ebe18ddb68feb22a760 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 2f52828cd17068135575bc2bd84e2afebae5e214
+Subproject commit 0ac98783691bbf8212537ebe18ddb68feb22a760