Update tokenizer_config.json

tokenizer_config.json

@@ -30,7 +30,7 @@
     "<|im_start|>",
     "<|im_end|>"
   ],
-  "bos_token": null,
+  "bos_token": "<|im_start|>",
   "chat_template": "{% if not add_generation_prompt is defined %}{% set add_generation_prompt = false %}{% endif %}{% for message in messages %}{{'<|im_start|>' + message['role'] + '\n' + message['content'] + '<|im_end|>' + '\n'}}{% endfor %}{% if add_generation_prompt %}{{ '<|im_start|>assistant\n' }}{% endif %}",
   "clean_up_tokenization_spaces": false,
   "eos_token": "<|im_end|>",