Update to the newest gnulib.

diff --git a/gnulib b/gnulib
index 93b78ec081ff9e5be8f4cdcc44dd4f6f5da15164..2923106da77d300a8385ca804daf9b8073f7edef 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 93b78ec081ff9e5be8f4cdcc44dd4f6f5da15164
+Subproject commit 2923106da77d300a8385ca804daf9b8073f7edef