Update tokenizer_config.json

tokenizer_config.json

@@ -25,6 +25,14 @@
       "rstrip": false,
       "single_word": false,
       "special": true
+    },
+    "3": {
+      "content": "<END>",
+      "lstrip": false,
+      "normalized": false,
+      "rstrip": false,
+      "single_word": false,
+      "special": true
     }
   },
   "bos_token": "<s>",