Fix logout from current resulting in black screen after switching to reused VC

Closes #489

Tusker/Screens/Main/AccountSwitchingContainerViewController.swift

@@ -123,6 +123,7 @@ class AccountSwitchingContainerViewController: UIViewController {
                     oldRoot.view.transform = CGAffineTransform(translationX: 0, y: -newInitialOffset).scaledBy(x: scale, y: scale)
                     newRoot.view.transform = .identity
                 } completion: { (_) in
+                    oldRoot.view.transform = .identity
                     oldRoot.additionalSafeAreaInsets = origAdditionalSafeAreaInsets
                     oldRoot.removeViewAndController()
                     newRoot.view.layer.masksToBounds = false