[NMT] Riva deployment issues of model built with nemo:23.03
I understand the this is not the primary issue tracker for Riva (I've posted an issue in the forum https://forums.developer.nvidia.com/t/riva-2-11-0-nemo-23-03-unable-to-deploy-nmt/256169).

Since I can not pinpoint from where the issue arises, I am posting here as well.

Trying to deploy a nemo NMT AAYN model built using `nemo:23.03`, the deploy fails. Riva does not load, the reported error is
```
UNAVAILABLE: Invalid argument: model 'nmt-classifier', tensor 'log_probs': the model expects 3 dimensions (shape [-1,-1,64000]) but the model configuration specifies 3 dimensions (an initial batch dimension because max_batch_size > 0 followed by the explicit tensor shape, making complete shape [-1,-1,32000])
```

I've managed to track down the issue to line 96 in `/usr/local/lib/python3.8/dist-packages/servicemaker/triton/nmt.py`, which sets a hardcoded value of `[-1,32000]` for the `log_probs` output in the classifier. If I change the value in the classifier `.pbtxt` by hand, the model loads and works as it should.

However, I'm unable to find where does the number of 64000 in my case come from. Is it from the target language tokenizer (in my case its size is 64000 tokens)? 