fix 'BitsAndBytesConfig' object is not subscriptable issue

modeling_baichuan.py

@@ -528,7 +528,7 @@ class BaichuanForCausalLM(BaichuanPreTrainedModel):
         self.model = BaichuanModel(config)
 
         self.lm_head = NormHead(config.hidden_size, config.vocab_size, bias=False)
-        if hasattr(config, "quantization_config") and config.quantization_config['load_in_4bit']:
+        if hasattr(config, "quantization_config") and isinstance(config.quantization_config, dict) and config.quantization_config.get('load_in_4bit', False):
             try:
                 from .quantizer import quantize_offline, init_model_weight_int4
             except ImportError: