Update COPYING.GPLv2 to reflect current FSF GPLv2.

The license text and terms do not change, but the document has been
updated, to reflect the FSF's current contact points, and to change 
the example name, under the "How to apply..." part, to "Moe Ghoul".

This reflects the FSF's own change, in the www.gnu.org CVS repo, at
https://web.cvs.savannah.gnu.org/viewvc/www/www/licenses/old-licenses/gpl-2.0.txt?annotate=1.5

Fixes #7749.

COPYING.GPLv2

@@ -2,7 +2,7 @@
                        Version 2, June 1991
 
  Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ <https://fsf.org/>
  Everyone is permitted to copy and distribute verbatim copies
  of this license document, but changing it is not allowed.
 
@@ -304,8 +304,7 @@ the "copyright" line and a pointer to where the full notice is found.
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License along
-    with this program; if not, write to the Free Software Foundation, Inc.,
-    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+    with this program; if not, see <https://www.gnu.org/licenses/>.
 
 Also add information on how to contact you by electronic and paper mail.
 
@@ -329,8 +328,8 @@ necessary.  Here is a sample; alter the names:
   Yoyodyne, Inc., hereby disclaims all copyright interest in the program
   `Gnomovision' (which makes passes at compilers) written by James Hacker.
 
-  <signature of Ty Coon>, 1 April 1989
-  Ty Coon, President of Vice
+  <signature of Moe Ghoul>, 1 April 1989
+  Moe Ghoul, President of Vice
 
 This General Public License does not permit incorporating your program into
 proprietary programs.  If your program is a subroutine library, you may