update tokenizer config

tokenizer_config.json

@@ -60,7 +60,7 @@
   "model_max_length": 512,
   "padding_side": "right",
   "special_tokens_map_file": "special_tokens_map.json",
-  "use_fast": true
+  "use_fast": true,
   "truncation_side": "right",
   "truncation_strategy": "longest_first",
   "unk_token": "<unk>"