title: HTTPS iframe shows as HTTP (mixed content)
body: <p>I've an iframe with a HTTPS URL which shows up as HTTP. I can't seem to figure out why it shows my HTTPS link as HTTP and therefore throwing a mixed content error. Thanks in advance.</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
  &lt;script type="text/javascript"&gt;
  //&lt;![CDATA[
  try{if (!window.CloudFlare) {var CloudFlare=[{verbose:0,p:0,byc:0,owlid:"cf",bag2:1,mirage2:0,oracle:0,paths:{cloudflare:"/cdn-cgi/nexp/dok3v=1613a3a185/"},atok:"648d22a7cbd8d39ff6c1d603172e4867",petok:"c4b2f316536247173a516f5b497b137d814de31b-1441717697-86400",betok:"907c8bfe67d347db6e2954b8e5aae965c633df1e-1441717697-120",zone:"addmilk.nl",rocket:"0",apps:{"ga_key":{"ua":"UA-64317812-1","ga_bs":"2"}}}];!function(a,b){a=document.createElement("script"),b=document.getElementsByTagName("script")[0],a.async=!0,a.src="//ajax.cloudflare.com/cdn-cgi/nexp/dok3v=e9627cd26a/cloudflare.min.js",b.parentNode.insertBefore(a,b)}()}}catch(e){};
  //]]&gt;
  &lt;/script&gt;
  &lt;script type="text/javascript"&gt;
  /* &lt;![CDATA[ */
  var _gaq = _gaq || [];
  _gaq.push(['_setAccount', 'UA-64317812-1']);
  _gaq.push(['_trackPageview']);
  
  (function() {
  var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
  ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
  var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
  })();
  
  (function(b){(function(a){"__CF"in b&amp;&amp;"DJS"in b.__CF?b.__CF.DJS.push(a):"addEventListener"in b?b.addEventListener("load",a,!1):b.attachEvent("onload",a)})(function(){"FB"in b&amp;&amp;"Event"in FB&amp;&amp;"subscribe"in FB.Event&amp;&amp;(FB.Event.subscribe("edge.create",function(a){_gaq.push(["_trackSocial","facebook","like",a])}),FB.Event.subscribe("edge.remove",function(a){_gaq.push(["_trackSocial","facebook","unlike",a])}),FB.Event.subscribe("message.send",function(a){_gaq.push(["_trackSocial","facebook","send",a])}));"twttr"in b&amp;&amp;"events"in twttr&amp;&amp;"bind"in twttr.events&amp;&amp;twttr.events.bind("tweet",function(a){if(a){var b;if(a.target&amp;&amp;a.target.nodeName=="IFRAME")a:{if(a=a.target.src){a=a.split("#")[0].match(/[^?=&amp;]+=([^&amp;]*)?/g);b=0;for(var c;c=a[b];++b)if(c.indexOf("url")===0){b=unescape(c.split("=")[1]);break a}}b=void 0}_gaq.push(["_trackSocial","twitter","tweet",b])}})})})(window);
  /* ]]&gt; */
  &lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;iframe src="https://cdn.addmilk.nl/track?id=1&amp;amp;preview_id=150908_thuiscomfort_tell_badkamer_728x90&amp;amp;preview_name=Thuiscomfort%20-%20Tell%20-%20Badkamer%20-%20728x90" frameborder="0" width="1" height="1"&gt;&lt;/iframe&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>I get the following error when loading the page even though my src URL is loaded over HTTPS:</p>
  
  <blockquote>
    <p>Mixed Content: The page at '<a href="https://demo.addmilk.nl/test.html" rel="nofollow">https://demo.addmilk.nl/test.html</a>' was
    loaded over HTTPS, but requested an insecure resource
    '<a href="http://cdn.addmilk.nl/track/?id=1&amp;preview_id=150908_thuiscomfort_tell_badkamer_728x90&amp;preview_name=Thuiscomfort%20-%20Tell%20-%20Badkamer%20-%20728x90" rel="nofollow">http://cdn.addmilk.nl/track/?id=1&amp;preview_id=150908_thuiscomfort_tell_badkamer_728x90&amp;preview_name=Thuiscomfort%20-%20Tell%20-%20Badkamer%20-%20728x90</a>'.
    This request has been blocked; the content must be served over HTTPS.</p>
  </blockquote>