maint: update to latest gnulib

* .gnulib: Update to latest, prior to freeze.

diff --git a/.gnulib b/.gnulib
index 2a9edc6f2b02a05553d266117ddee80b3e0a3749..d245e6ddd6ab2624d0d83acd8f111454f984f50f 160000 (submodule)
--- a/.gnulib
+++ b/.gnulib
@@ -1 +1 @@
-Subproject commit 2a9edc6f2b02a05553d266117ddee80b3e0a3749
+Subproject commit d245e6ddd6ab2624d0d83acd8f111454f984f50f