[COOK-2870] Put Port directive at the top of sshd_config to be compatible with Ruby 1.8

Port directive must be placed before ListenAddress directive according to the result of 'sshd -t' as described in COOK-2870. Unfortunately Ruby 1.8 doesn't keep the order of Hash elements while 1.9 supports it. This PR changes sshd_config template to place Port directive at the beginning of the file.