Embed URLs are http which break mixed content rules on encrypted sites

[eudoxos]

When q2a is accessed over https, embeds with http are not displayed -- as a result of Mixed content (http://www.w3.org/TR/mixed-content/) blocking which is on by default in Firefox since some time (and in other browsers, too).

I was able to work around the issue for a site using https exclusively by replacing the protocol in by hand (e.g. in https://github.com/NoahY/q2a-embed/blob/master/qa-embed-layer.php#L51).

The code should find out whether it is accessed through an encrypted connection or not, and use http or https for embedded URLs based on that.

[Alvarofg]

I just replaced http:// with just // to let the browser figure out the protocol