Fixed ket generation from a list with Qobj

I used to be that `Qobj([1,2])` and `Qobj([[1,2]])` gives the same result, a `type=bra` state.

Now the former produces `type=ket` state.

And now it is consistent with generation `Qobj(np.array([1,2]))` and `Qobj(np.array([[1,2]]))`, respectively.