maint: update gnu-web-doc-update.

* gnulib: here.

diff --git a/gnulib b/gnulib
index cabce6b8f2042e42c2098f7cf18873c61ac7bcd5..2f67aa79c6f13961eda685144130692dc9f7b95f 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit cabce6b8f2042e42c2098f7cf18873c61ac7bcd5
+Subproject commit 2f67aa79c6f13961eda685144130692dc9f7b95f