title: URLs within CSS files broken with Grails resources plugin 1.2.7
body: <p>Recently upgraded a grails project to 2.3.7 and plugins to their newest, which has brought Resources plugin to 1.2.7.  This worked fine with Grails 2.1.2 and resources plugin 1.2RC3, but now it is not:</p>
  
  <p>whenever I have a css file that references something via a URL like this</p>
  
  <pre><code>.checkbox-input-wrap.checked {
    background-image: url(/img/uniform-assets/checkbox.png);
  }
  </code></pre>
  
  <p>On the webpage it leads to this error (it is leaving 'resource:/' on the front of the URL)</p>
  
  <blockquote>
    <p>GET resource:/img/uniform-assets/checkbox.png net::ERR_UNKNOWN_URL_SCHEME </p>
  </blockquote>