Update tokenizer_config.json

tokenizer_config.json

@@ -1 +1 @@
-{"unk_token": "[UNK]", "pad_token": "[PAD]", "do_lower_case": true, "return_attention_mask": true, "do_normalize": true}
+{"unk_token": "[UNK]", "pad_token": "<pad>", "do_lower_case": true, "return_attention_mask": true, "do_normalize": true}