iOS: incorrect `isTorchOn` after switching camera

In case you’re currently using back camera on iPhone device
then turn flash on WOWZCamera.isTorchOn = true
then switch to front camera (which doesn’t have flash) and again to back camera WOWZCameraPreview.switchCamera()
the value of WOWZCamera.isTorchOn is still true but actual device doesn’t have flash on.