When unit is in "enter" phase and it was called SetNextState we have to return true in order to abort current state
From FSM.js:
```
"enter": function() {
// This is a special function called when transitioning
// into this state, or into a substate of this state.
//
// If it returns true, the transition will be aborted:
// do this if you've called SetNextState inside this enter
// handler, because otherwise the new state transition
// will get mixed up with the previous ongoing one.
// In normal cases, you can return false or nothing.
},
```