title: Django static_url when script_name set?
body: <p>So I'm trying to run multiple instances of Django on a server for now, one under <code>/dev/</code>, one under <code>/test/</code>, etc.. </p>
  
  <p>The web server is setting the correct <code>SCRIPT_NAME</code> setting and I can serve pages, templates, the whole admin panel fine, except for static assets. Static assets are served by Django using WhiteNoise. </p>
  
  <p>The application is supposed to use the value of <code>SCRIPT_NAME</code> as the static URL, ie all static assets are served from the application root.</p>
  
  <p>So far I've tried the following settings against the admin panel:</p>
  
  <pre><code># SCRIPT_NAME = '/dev/' Set in env
  # URL for static assets should be `/dev/`
  STATIC_URL = '/'  # Browser looks for static assets in `/`, drops script_name
  STATIC_URL = None # Browser looks for static assets in `/`, drops script_name
  STATIC_URL = `/dev/` # Browser looks for static assets in '/dev/dev/`
  </code></pre>
  
  <p>I'm wondering if I'm missing a setting here or if the problem might be elsewhere. Going by the docs I understand that <code>STATIC_URL = '/'</code> should work?</p>