C3 crash moving an event contains a special Tween action.

Hello folks,

I've submitted a bug report because I have seen that when you move an action containing a tween behavior with a customized Ease will crash your browser.

More details and a .c3p test file can be checked here:

https://github.com/Scirra/Construct-3-bugs/issues/3561

Be careful when you move an event like this!