fix bug for contextual train

shixian.shi

2023-11-24 34b2682fba92bf4f8e163d22094e7de57e3290ca

 funasr/models/encoder/abs_encoder.py

@@ -18,4 +18,4 @@
        ilens: torch.Tensor,
        prev_states: torch.Tensor = None,
    ) -> Tuple[torch.Tensor, torch.Tensor, Optional[torch.Tensor]]:
        raise NotImplementedError
        raise NotImplementedError