Update README.md

Author: welleast

README.md

@@ -191,7 +191,7 @@ If you find this work or code is helpful in your research, please cite:
 
 ## Reference
 [1] Deep High-Resolution Representation Learning for Visual Recognition. Jingdong Wang, Ke Sun, Tianheng Cheng, 
-    Borui Jiang, Chaorui Deng, Yang Zhao, Dong Liu, Yadong Mu, Mingkui Tan, Xinggang Wang, Wenyu Liu, Bin Xiao. [download]  (https://arxiv.org/pdf/1908.07919.pdf)
+    Borui Jiang, Chaorui Deng, Yang Zhao, Dong Liu, Yadong Mu, Mingkui Tan, Xinggang Wang, Wenyu Liu, Bin Xiao. [download](https://arxiv.org/pdf/1908.07919.pdf)
 
 ## Acknowledgement
 We adopt ~~sync-bn implemented by [InplaceABN](https://github.com/mapillary/inplace_abn).~~ the PyTorch official syncbn.