receiver/iframe: don't sandbox iframes

This may seem a good idea to avoid iframes doing crazy stuff but some
perfectly valid uses are just blocked. For example, it is not possible
for an iframe to change its origin to a super domain (edition.cnn.com
is not allowed to change its domain to cnn.com when it should).

app/scripts/receiver/iframe-queue.js

@@ -33,7 +33,6 @@ module.exports = (function(window, undefined) {
     vp.adapt(this.el);
 
     // Load the URL
-    this.el.setAttribute('sandbox', 'allow-scripts allow-same-origin');
     this.el.setAttribute('src', dashboard.url);
   }