Please update CVS download instructions

[Pavel Roskin]

Hello!

Please see https://savannah.gnu.org/forum/forum.php?forum_id=4168 for
details.

Since pserver is used, CVS_RSH is not needed.  The commands for initial
CVS checkout are following:

for GRUB legacy:
cvs -z3 -d:pserver:address@hidden:/cvsroot/grub co grub

for GRUB2:
cvs -z3 -d:pserver:address@hidden:/cvsroot/grub co grub2

URLs to be updated:
http://www.gnu.org/software/grub/grub-legacy-download.en.html
http://www.gnu.org/software/grub/grub-2-download.en.html

-- 
Regards,
Pavel Roskin