After changing position of tab navigation impacted , routerFlux , react-native

### Version

- react-native-router-flux v4.?.?
- react v16.?.?
- react-native v0.?.?

### Expected behaviour
It should just change the tabs position and navigation should work like earlier .

### Actual behaviour
When going into nested screen and pressing back it is by default opening the route screen of 3rd tab.

Please help , quick help will be appreciated.

Thanks
Ashish Jaiswal
[file.zip](https://github.com/aksonov/react-native-router-flux/files/5829614/file.zip)