build: update from gnulib, for the vc-list-files fix

* gnulib: Update submodule to latest.

diff --git a/gnulib b/gnulib
index b54016675fd7e8e6b36444cde8ac85ff6302c7ff..c335e0ec67853b066fae56f6c61b0dbde4c71d74 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit b54016675fd7e8e6b36444cde8ac85ff6302c7ff
+Subproject commit c335e0ec67853b066fae56f6c61b0dbde4c71d74