Update to the newest gnulib.

diff --git a/gnulib b/gnulib
index 0346e2edf270eeef64bc537136b20ff07f3ecf27..981d04f93ea75c85609c18a6dcdb13cce8f07e05 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 0346e2edf270eeef64bc537136b20ff07f3ecf27
+Subproject commit 981d04f93ea75c85609c18a6dcdb13cce8f07e05