Repository: huggingface/transformers
Pull request: Update ModelType for Unigram tokenizer

# What does this PR do?

When tokenizer is red from `tokenizer.model` then model type whether it's `Unigram` or `BPE` is done incorrectly. 
Correct Unigram model type is 1 not 2 according to `SentencePiece` src
https://github.com/google/sentencepiece/blob/master/src/sentencepiece_model.proto#L48-L52


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Changed files:
filename: src/transformers/convert_slow_tokenizer.py
patch: @@ -169,7 +169,7 @@ def extract(self, model_type, **kwargs) -> tuple[dict[str, int], list[tuple]]:
         if model_type is None:
             from tokenizers.models import BPE, Unigram
 
-            model_type = Unigram if self.proto.trainer_spec.model_type == 2 else BPE
+            model_type = Unigram if self.proto.trainer_spec.model_type == 1 else BPE
         vocab = [(piece.piece, piece.score) for piece in self.proto.pieces]
 
         if model_type.__name__ != "BPE":