[Catalog] External Content Item does not work for newer browser version when target is within catalog

Browser versions Firefox 24 and Chrome 30.0.1599.101 block an external link when the target is within the catalog. (Not related to a particular release. It is a as a browser security feature.) When the link is HTTPS, there is a javascript error. When the link is HTTP, there is a warning in the console.

1. Create a new content item.
   1. Content Type: External Content
   2. Target: Within Catalog
   3. URL: http://www.google.co.uk/
2. Go to Service Catalog homepage and click on the Content Item created previously.
   • Note that the page does not load
   • Note that there is a warning in the browser console
3. Repeat steps 1a and 1b.
   • Set URL to https://www.google.co.uk/
4. Open the content item from the catalog homepage.
   • Note that the page does not load
   • Note that there is a warning in the browser console

The target should be set to New Window/Tab when the URL links to external content that is not in the same domain.