replace invalid link

Author: donglihe-hub

example_config/EUR-Lex-57k/README.md

@@ -11,4 +11,4 @@ The best model is selected by **RP@5** on validation set then evaluated on test
 |     Kim-CNN     | [Chen et al. 2022](https://www.csie.ntu.edu.tw/~cjlin/papers/xmlcnn/xml_cnn_study.pdf) |     20.0767     |     69.9073     |     90.7833     |     66.8733     |     77.5347     |     80.3488     | [Cfg](./kim_cnn.yml) | 30 mins |
 |     CNN-LWAN     | [Mullenbach et al. 2018](https://aclanthology.org/N18-1100/) |     26.3245     |     71.6865     |     89.8167     |     67.3100     |     78.0261     |     80.5446     | [Cfg](./cnn_lwan.yml) | 2 hrs |
 |     BiGRU-LWAN     | [Chalkidis et al. 2019](https://aclanthology.org/P19-1636/) |     25.4260     |     71.3199     |     90.7333     |     67.0800     |     77.7506     |     80.5999     | [Cfg](./bigru_lwan.yml) | 3 hrs 20 mins |
-|     BERT-BASE-LWAN     | [Chalkidis et al. 2020](http://aclanthology.lst.uni-saarland.de/2020.emnlp-main.607/) |     26.1981     |     72.7849     |     89.9833     |     67.8533     |     78.4742     |     80.9834     | [Cfg](./bert_lwan.yml) | 9 hrs |
+|     BERT-BASE-LWAN     | [Chalkidis et al. 2020](https://aclanthology.org/2020.emnlp-main.607/) |     26.1981     |     72.7849     |     89.9833     |     67.8533     |     78.4742     |     80.9834     | [Cfg](./bert_lwan.yml) | 9 hrs |