Undo paste causes <ins> tags to be removed

[ktundwal]

Repro steps (also see attached recording)

1. Insert 3 paras in editor
2. Copy first 2 paras
3. Enable change tracking via button on toolbar
4. Paste copied text after para 3
5. Ensure pasted text is highlighted as "insert" change tracking
6. Add space within pasted text
7. Press Ctrl-Z once to Undo

Behavior
Space is remove. 'ins' tag is also deleted. See status bar below

Expected behavior
Only space is expected to be removed. NOT ins tag

[scottleibrand]

Looks like you opened this under the wrong project. This is Loopkit/Loop, not https://github.com/ckeditor