Update to a newer gnulib.

diff --git a/gnulib b/gnulib
index 93fcf9072a0eb904d3c34405dbdfe7815402fbba..7d7fd2084fb18f19c8cc79543ed9d73a93984877 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 93fcf9072a0eb904d3c34405dbdfe7815402fbba
+Subproject commit 7d7fd2084fb18f19c8cc79543ed9d73a93984877