Ending a bullet/number list at the end of a document is not possible in FF

[damo]

Steps to reproduce:

1. Open Ajax example
   
2. Select all content and remove it
   
3. Select the bullet list option and create a list with several items
   
4. Press ENTER to create an empty item and BACKSPACE to delete it and end the list
   

Expected results:
The list mode should turn off and the last empty bullet should be deleted.

Actual result:
The list does not end; the bullet toolbar option must be used to end the list.

FF only.

[highjinx_53]

This is a duplicate of #3312.