fix bug when model_type not explicitly passed

src/axolotl/utils/models.py

@@ -35,7 +35,7 @@ def load_model(
     # TODO refactor as a kwarg
     load_in_8bit = cfg.load_in_8bit
     tokenizer = None
-    is_llama_derived_model = "llama" in base_model or "llama" in cfg.model_type.lower()
+    is_llama_derived_model = "llama" in base_model or (cfg.model_type and "llama" in cfg.model_type.lower())
 
     if is_llama_derived_model and cfg.flash_attention:
         if cfg.device not in ["mps", "cpu"] and inference is False: