build: update gnulib submodule to latest

diff --git a/gnulib b/gnulib
index 30784c47105573c213cda1b3c4f397c8df837966..8edebfe6f97d0e378d042accb2475a32a53f100f 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 30784c47105573c213cda1b3c4f397c8df837966
+Subproject commit 8edebfe6f97d0e378d042accb2475a32a53f100f