gnulib: sync with upstream.

* gnulib: Sync with upstream.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>

diff --git a/gnulib b/gnulib
index a39d4083cab589d7cd6a13e8a4b8db8875261d75..8415b6792e53f9aa309caedda799f9d9f3dffc53 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit a39d4083cab589d7cd6a13e8a4b8db8875261d75
+Subproject commit 8415b6792e53f9aa309caedda799f9d9f3dffc53