fixes #4304 - popup.params sometimes undefined

[scp]

In core/vanilla - seeing this error from iOS users - managed to track it down to specifically when users use the iOS app switcher/or the app loses focus whilst the popup is open - when user returns to the app the error is triggered:

undefined is not an object (evaluating 'i.params.swipeToClose')

[nolimits4web]

The question is why in your app they end up like this? In your console log it specifically says that popup is destroyed. I guess you shouldn't destroy it then if you still need it

[scp]

Thanks for the pointer @nolimits4web - the app automatically navigates to another page on receiving app focus.

When there is a popup previously on the screen, the navigation must cause the popup to be destroyed, but it also generates this error.

I've changed the navigation logic for when there is a modal on screen to avoid the error.