Update tokenizer_config.json

tokenizer_config.json

@@ -62,6 +62,6 @@
   "tokenizer_class": "GPT2Tokenizer",
   "truncation_side": "left",
   "trust_remote_code": false,
-  "unk_token": "<unk>"
+  "unk_token": "<unk>",
   "sep_token": "<sep>"
 }