title: previous URL document.referrer is empty
body: <p>I have saved link on this page: <a href="https://sites.google.com/site/sanccvfx/home" rel="nofollow noreferrer">https://sites.google.com/site/sanccvfx/home</a></p>
  
  <p><a href="http://127.0.0.1:5000" rel="nofollow noreferrer">http://127.0.0.1:5000</a> and <a href="http://192.168.1.2:5000" rel="nofollow noreferrer">http://192.168.1.2:5000</a></p>
  
  <p>but when I capture using <code>document.referrer</code> the come out to be empty string instead of from where they are coming.</p>