fix onnx export bug

hnluo

2023-08-29 72b6c7735e44fff12c4a3d401deb98c59f16ab0f

 funasr/layers/abs_normalize.py

@@ -11,4 +11,4 @@
        self, input: torch.Tensor, input_lengths: torch.Tensor = None
    ) -> Tuple[torch.Tensor, torch.Tensor]:
        # return output, output_lengths
        raise NotImplementedError
        raise NotImplementedError