updated the server upgrade page refering to PR:2809
updated the server upgrade page refering to PR:2809

Signed-off-by: Dishank Tiwari <2570983f455e95db564060b7b5b916a0b85a4357@users.noreply.github.com>

chef/chef-server,chef/chef-server,chef/chef-server,chef/chef-server,chef/chef-server,chef/chef-server