[COOK-3316] Fix README.md example
[COOK-3316] Fix README.md example

Signed-off-by: Seth Vargo <81550dbf04dfd8537ff7b3c014c6fbf86e0889dc@gmail.com>

phusion/ufw,opscode-cookbooks/ufw,rastasheep/ufw,cla-rce/ufw,chef-cookbooks/ufw,boardiq/ufw