Undo doesn't remove adding an OR condition

Add an OR condition into an event, do UNDO, doesn't register it.

There also seems to be no way to remove an added OR event.

I can confirm you can't undo the added OR condition, but removing OR is simply choosing "make AND block".

[Ashley]

Closing as duplicate of https://www.scirra.com/forum/can-t-undo-quot-make-or-block-quot-action-or-block-not-showing_t189573