title: Chef update config file
body: <p>I have a chef cookbook which installs nginx and install a custom nginx.conf file. It's basically the same cookbook on Opscode, and uses cookbook_file to install the file.</p>
  
  <p>If I make a change to the conf file, then rerun the cookbook using chef the configuration file isn't updated.  This seems like a bug -- am I doing something wrong?</p>