Replace arxiv link to abstract

README.md

@@ -786,7 +786,7 @@ dataset_info:
 ## Dataset Description
 
 - **Homepage:** [XGLUE homepage](https://microsoft.github.io/XGLUE/)
-- **Paper:** [XGLUE: A New Benchmark Dataset for Cross-lingual Pre-training, Understanding and Generation](https://arxiv.org/pdf/2004.01401.pdf)
+- **Paper:** [XGLUE: A New Benchmark Dataset for Cross-lingual Pre-training, Understanding and Generation](https://arxiv.org/abs/2004.01401)
 
 ### Dataset Summary