build: update gnulib submodule to latest

diff --git a/gnulib b/gnulib
index 5b92dd0a45c8d27f13a21076b57095ea5e220870..3c893dc1b075bc874c325f0dea0cd0bcb46715c1 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 5b92dd0a45c8d27f13a21076b57095ea5e220870
+Subproject commit 3c893dc1b075bc874c325f0dea0cd0bcb46715c1