title: Grails "war" command, how to set system property
body: <p>I'm running <code>grails prod war</code> to create my app's <code>.war</code> file.  The problem is, I need to somehow set a system property that can be accessed in <code>grails-app/conf/Config.groovy</code> when that .war is being built.</p>
  
  <p>How can I do this?  Grails version 2.1.0</p>