fix(openvoice): correctly set utterance length (#260)

Author: eginhard

TTS/vc/models/openvoice.py

@@ -226,7 +226,7 @@ def eval_step(self) -> None: ...
     def _set_x_lengths(x: torch.Tensor, aux_input: Mapping[str, Optional[torch.Tensor]]) -> torch.Tensor:
         if "x_lengths" in aux_input and aux_input["x_lengths"] is not None:
             return aux_input["x_lengths"]
-        return torch.tensor(x.shape[1:2]).to(x.device)
+        return torch.tensor(x.shape[-1:]).to(x.device)
 
     @torch.inference_mode()
     def inference(