title: Prevent blocking of redirect from https to http in service worker
body: <p>I have been working on implementing a service worker to add some caching benefits to our site and all has been going well apart from one particular page on the site.</p>
  
  <p>This page is linked to as <a href="https://domain/path" rel="nofollow">https://domain/path</a>  but a server side redirect looks to redirect this to <a href="http://domain/path/" rel="nofollow">http://domain/path/</a> and this point the service worker is blocking the request. When the link is clicked the page puts out a <code>This webpage is not available</code> error and the console shows the following:</p>
  
  <pre><code>Mixed Content: The page at 'https://domain.com/service-worker.js' was loaded over HTTPS, but requested an insecure resource 'http://domain.com/path/'. This request has been blocked; the content must be served over HTTPS.
  </code></pre>
  
  <p>Ideally we will be looking to ensure that redirect stays on https, but while that issue is resolved is there a way of working around this within the service worker?</p>