gnulib: update submodule to new repository.

* configure.ac: Update autoconf requirement for bootstrapping to 2.64.
* README.md: Update note concerning autoconf version requirement.
* bootstrap: Propogate change to GPL license from GPL 3 to GPL 2.

.gitmodules

@@ -1,6 +1,6 @@
 [submodule "gnulib"]
         path = gnulib
-        url = git://git.sv.gnu.org/gnulib.git
+        url = git://git.savannah.gnu.org/gnulib.git
 [submodule "bootstrap"]
         path = gl-mod/bootstrap
         url = https://github.com/gnulib-modules/bootstrap.git

README.md

@@ -191,7 +191,7 @@ send the file `tests/testsuite.log` to the [bug mailing list][].
           co -d libtool HEAD
 
 * Before you can build from git, you need to bootstrap.  This requires:
-  - Autoconf 2.62 or later
+  - Autoconf 2.64 or later
   - Automake 1.11.1 or later
   - Help2man 1.29 or later
   - Xz 4.999.8beta or later (from [tukaani.org](http://tukaani.org/xz))

bootstrap

@@ -12,7 +12,7 @@
 # Copyright (C) 2010-2019, 2021 Bootstrap Authors
 #
 # This file is dual licensed under the terms of the MIT license
-# <https://opensource.org/license/MIT>, and GPL version 3 or later
+# <https://opensource.org/license/MIT>, and GPL version 2 or later
 # <http://www.gnu.org/licenses/gpl-2.0.html>.  You must apply one of
 # these licenses when using or redistributing this software or any of
 # the files within it.  See the URLs above, or the file `LICENSE`
@@ -238,7 +238,7 @@ scriptversion=2019-02-19.15; # UTC
 # Copyright (C) 2004-2019, 2021 Bootstrap Authors
 #
 # This file is dual licensed under the terms of the MIT license
-# <https://opensource.org/license/MIT>, and GPL version 3 or later
+# <https://opensource.org/license/MIT>, and GPL version 2 or later
 # <http://www.gnu.org/licenses/gpl-2.0.html>.  You must apply one of
 # these licenses when using or redistributing this software or any of
 # the files within it.  See the URLs above, or the file `LICENSE`
@@ -1702,7 +1702,7 @@ func_lt_ver ()
 # Copyright (C) 2010-2019, 2021 Bootstrap Authors
 #
 # This file is dual licensed under the terms of the MIT license
-# <https://opensource.org/license/MIT>, and GPL version 3 or later
+# <https://opensource.org/license/MIT>, and GPL version 2 or later
 # <http://www.gnu.org/licenses/gpl-2.0.html>.  You must apply one of
 # these licenses when using or redistributing this software or any of
 # the files within it.  See the URLs above, or the file `LICENSE`
@@ -2387,7 +2387,7 @@ func_version ()
 # Copyright (C) 2010-2019, 2021 Bootstrap Authors
 #
 # This file is dual licensed under the terms of the MIT license
-# <https://opensource.org/license/MIT>, and GPL version 3 or later
+# <https://opensource.org/license/MIT>, and GPL version 2 or later
 # <http://www.gnu.org/licenses/gpl-2.0.html>.  You must apply one of
 # these licenses when using or redistributing this software or any of
 # the files within it.  See the URLs above, or the file `LICENSE`

configure.ac

@@ -24,7 +24,7 @@
 ####
 
 
-AC_PREREQ(2.63)
+AC_PREREQ(2.64)
 dnl Oldest automake required for bootstrap is below in AM_INIT_AUTOMAKE.
 
 

gnulib

@@ -1 +1 @@
-Subproject commit 426f44034396d52d6981f3c6e79e089bbacce645
+Subproject commit a5218207e5f92e152a34994cce4aa415b1eb25c8

m4/.gitignore

@@ -4,3 +4,4 @@
 /gnulib-comp.m4
 /gnulib-tool.m4
 /ltversion.m4
+/zzgnulib.m4