build: update gnulib for FreeBSD build

Several gnulib tests were failing 'make check', and compilation with
CFLAGS=-g failed due to a gcc 4.2.1 limitation.

* .gnulib: Update to latest, for gcc 4.2 support and fixed FreeBSD tests.

diff --git a/.gnulib b/.gnulib
index b4938324b7113c9d73f8390d21f3ecbd842e74b9..2a9edc6f2b02a05553d266117ddee80b3e0a3749 160000 (submodule)
--- a/.gnulib
+++ b/.gnulib
@@ -1 +1 @@
-Subproject commit b4938324b7113c9d73f8390d21f3ecbd842e74b9
+Subproject commit 2a9edc6f2b02a05553d266117ddee80b3e0a3749