fix: use rootNavigator = true when close web3 modal

[mthinh]

Hi @quetool , I'm opening this pull request to resolve an issue when closeModal is called, The thing is we open the modal using rootNavigator = true, it means when we close the modal, we should use rootNavigator = true also, otherwise it may affect to current navigation stack, and returns a blank screen. Please help to take a look and resolve.

What ?

• use rootNavigator = true when close web3 modal

Why ?

• Navigator.pop without using rootNavigator sometimes make the navigation system returns the blank screen

reference: https://stackoverflow.com/questions/53723294/flutter-navigator-popcontext-returning-a-black-screen

[quetool]

Hello @mthinh! This is now merged! Thank you and sorry for the delay!