maint: Use GNULIB_REVISION instead of git submodule.

.gitignore

@@ -28,6 +28,7 @@
 /config.status
 /configure
 /confpaths.h
+/gnulib/
 /include
 /inetutils-*.tar.*
 /inetutils-*/

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "gnulib"]
-	path = gnulib
-	url = https://git.savannah.gnu.org/git/gnulib.git

bootstrap.conf

@@ -16,6 +16,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see `http://www.gnu.org/licenses/'.
 
+GNULIB_REVISION=aacceb6eff58eba91290d930ea9b8275699057cf
+
 # Build prerequisites.
 buildreq="\
 autoconf   2.59