Update tokenizer_config.json

tokenizer_config.json

@@ -173,7 +173,7 @@
   "clean_up_tokenization_spaces": false,
   "eos_token": "</s>",
   "model_max_length": 8192,
-  "pad_token": "</s>",
+  "pad_token": "<unk>",
   "tokenizer_class": "InternLM2Tokenizer",
   "unk_token": "<unk>"
 }