hasLabel filtering should be able to filter OrientDB classes with inheritance model

For example i have this orientdb schema class inheritance
```
V -> VHeating -> VHeating_Elect
              -> VHeating_Gaz
```
In a traversal doing the step filter hasLabel("VHeating") should give me vertex from the 2 child classes (Elect and Gaz)

Now it gives only things that are only "VHeating"


                            