gnulib: Update submodule to recent commit

diff --git a/gnulib b/gnulib
index 30417e7f918e95c368ef56a650fa5b5fa45cb130..b3791b2bb9bdf03b2f99be5629d017a40382e1ee 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 30417e7f918e95c368ef56a650fa5b5fa45cb130
+Subproject commit b3791b2bb9bdf03b2f99be5629d017a40382e1ee