[WSC] Error when clicking "Finish Checking"

[Olek Nowodziński]

Steps to reproduce

1. Open samples/index.html (also ​http://ckeditor.com/demo)
2. Set the following data

   <p>asd</p>
   <p>zxc</p>
   <p>qwe</p>
   <p>asd</p>
   

3. From the SCAYT dropdown select "Enable SCAYT".
4. From the SCAYT dropdown select "Check Spelling".
5. Click "Change to".
6. Click "Change to".
7. Click "Finish Checking".

Expected result

Dialog closes. Back to editing content.

Actual result

Error in the console

getWordsInfockscayt.js:36:10529 TypeError: g.ltr is not an Object. (evaluating 'c in g.ltr')

Dialog does not close, just keeps displaying a spinner.

Other details (browser, OS, CKEditor version, installed plugins)

WSC Version: 3.0.7670

Tested in Chrome Version 46.0.2490.86 (64-bit), Safari Version 9.0.1 (11601.2.7.2)