Remove list broken with enterMode = BR

[garry.yao]

Originally reported by Martin, this related to #3773, but not a DUP.

1. Open the replace by code example page with enterMode = BR;
2. Make the content and selection as below:

   line1
   <ul><li>[item1</li><li>item2]</li></ul>
   line2
   

3. Click on 'Bullet List' to remove list;

• Expected Result:

  line1<br />
  item1<br />
  item2<br />
  line2
  

• Actual Result:

  line1item1item2line2
  

[garry.yao]

I would wait for the dependency #3773 to close first.

[martinkou]

Tidied up the list a bit.

[garry.yao]

Fixed with [3894].