[IE 9...10] Error on removing image from editor.

[Artur Delura]

Browser: [IE 9...10] Since: 4.4.4 ​http://presets.ckeditor.dev/4.4.4/standard/ckeditor/samples/replacebyclass.html

1. Open editor with following content:

   <h1><img src="assets/sample.jpg" />Apollo 11</h1>
   

2. Select image by clicking it.
3. Press backspace button to remove image.

Actual result: Error is throw in console:

SCRIPT5007: Unable to get value of the property 'equalsContent': object is null or undefined 
ckeditor.js, line 993 character 30