build: update gnulib submodule to latest

diff --git a/gnulib b/gnulib
index e9655b05dc0b25d24457f9b8dd31a579d6867d83..4602765093f04e597f87d78cf29d21eea03b6fa4 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit e9655b05dc0b25d24457f9b8dd31a579d6867d83
+Subproject commit 4602765093f04e597f87d78cf29d21eea03b6fa4