fix hangup for wait ack

[yeoleobun]

For UAS that sent 200 but have not received ACK, it can not CANCEL and also can not BYE.

    pub fn can_cancel(&self) -> bool {
        matches!(
            self,
            DialogState::Calling(_) | DialogState::Trying(_) | DialogState::Early(_, _)
        )
    }
    pub fn is_confirmed(&self) -> bool {
        matches!(self, DialogState::Confirmed(_, _))
    }