contrib/vim: change URL to point to the latest syntax files

Vim's SVN repository doesn't offer the latest runtime files, since
normally they are only updated there on a release. Though currently
there is no difference between the SVN and HTTP/FTP version of the git
syntax files.

Signed-off-by: Markus Heidelberg <markus.heidelberg@web.de>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/vim/README

@@ -5,11 +5,13 @@ automatically.
 If you have an older version of vim, you can get the latest syntax
 files from the vim project:
 
-  http://vim.svn.sourceforge.net/viewvc/vim/trunk/runtime/syntax/git.vim
-  http://vim.svn.sourceforge.net/viewvc/vim/trunk/runtime/syntax/gitcommit.vim
-  http://vim.svn.sourceforge.net/viewvc/vim/trunk/runtime/syntax/gitconfig.vim
-  http://vim.svn.sourceforge.net/viewvc/vim/trunk/runtime/syntax/gitrebase.vim
-  http://vim.svn.sourceforge.net/viewvc/vim/trunk/runtime/syntax/gitsendemail.vim
+  http://ftp.vim.org/pub/vim/runtime/syntax/git.vim
+  http://ftp.vim.org/pub/vim/runtime/syntax/gitcommit.vim
+  http://ftp.vim.org/pub/vim/runtime/syntax/gitconfig.vim
+  http://ftp.vim.org/pub/vim/runtime/syntax/gitrebase.vim
+  http://ftp.vim.org/pub/vim/runtime/syntax/gitsendemail.vim
+
+These files are also available via FTP at the same location.
 
 To install: