build: update gnulib submodule to latest

diff --git a/gnulib b/gnulib
index 1b55eda230418d81e8f3b346539f9ee4b6050b51..b8083ec2eeb22c20d299d75aae06e465cf9e4494 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 1b55eda230418d81e8f3b346539f9ee4b6050b51
+Subproject commit b8083ec2eeb22c20d299d75aae06e465cf9e4494