Make sure navigator is not null

```
System.InvalidOperationException: NavigationProvider cannot be null!
   at ff14bot.Navigation.Navigator.MoveTo(Vector3 location, String destination)
   at ff14bot.Managers.AvoidanceManager. ()
   at ff14bot.Managers.AvoidanceManager.Pulse()
   at ff14bot.Behavior.Pulsator.Pulse(PulseFlags CurrentPulseFlags)
   at ff14bot.TreeRoot. ()
```