Changing Path to CKEditor causes cdn url to be incorrect

By default, Path to CKEditor uses the cdn url to version 4.4.0 (//cdn.ckeditor.com/4.4.0/full-all). When viewing a wysiwyg-enabled field, ckeditor loads fine with no javascript errors. I wanted to test earlier versions of ckeditor so I set Path to CKEditor to version 4.3.1 (//cdn.ckeditor.com/4.3.1/full-all). When viewing the same wysiwyg-enabled field, ckeditor does not load and their are javascript errors.

From Chrome javascript console:

GET http://<drupal_base_url>//cdn.ckeditor.com/4.3.1/full-all/lang/en.js?t=DBAA 404 (Not Found) ckeditor.js:68
Uncaught TypeError: Cannot set property 'dir' of undefined ckeditor.js:200
GET http://<drupal_base_url>//cdn.ckeditor.com/4.3.1/full-all/skins/moono/editor.css?t=DBAA 404 (Not Found) ckeditor.js:68

As you can see, my site's base_url is being prepended to the cdn url when other ckeditor files are requested. That is breaking ckeditor.

Steps to reproduce:

1. Download ckeditor module 7.x-1.14
2. In the global ckeditor profile, set Path to CKEditor to //cdn.ckeditor.com/4.3.1/full-all
3. Try to edit a wysiwyg-enabled field