Column scope change event does not have associated tooltip

Steps to repro:

1. Have a status and transitions that are not mapped on the board. The unmapped status needs to have a transition to "Done"
2. Move an issue from Open to Unmapped
3. Burndown happens because of scope change
4. Then transition the issue to Resolved
5. *Event is shown because issue is now mapped again.

But you will notice that there is no tooltip for this change event, even though there is a row in the table.

I suspect this is because the delta is 0 (the issue was effectively burnt down when moving to unmapped status, and then when it moved back in, it was resolved)