fix load_params

convert-hf-to-gguf.py

@@ -1791,23 +1791,10 @@ class QwenModel(Model):
 class Qwen2Model(Model):
     model_arch = gguf.MODEL_ARCH.QWEN2
     
-    def __init__(self, dir_model: Path, ftype: int, fname_out: Path, is_big_endian: bool, use_temp_file: bool):
-        super().__init__(dir_model, ftype, fname_out, is_big_endian, use_temp_file)
-        self.hparams = Qwen2Model.load_hparams(dir_model)
-
-    @staticmethod
-    def load_hparams(dir_model):
-        with open(dir_model / "config.json", "r", encoding="utf-8") as f1, \
-            open(dir_model / "tokenizer_config.json", "r", encoding="utf-8") as f2:
-            hparams = json.load(f1)
-            hparams.update(json.load(f2))
-
-        return hparams
-    
     def set_vocab(self):
-        if self.hparams.get("tokenizer_class") == "PreTrainedTokenizerFast":
+        try:
             self._set_vocab_sentencepiece()
-        else:
+        except FileNotFoundError:
             self._set_vocab_gpt2()