As per tanxi requested, PCL asked to update the link to https://dw.pcl.ac.cn/dwmain/main/.

1. on the home page: https://openeuler.org/, both English and Chinese

2. on https://openeuler.org/zh/summit/2020-virtual-summit.html and https://openeuler.org/en/summit/2020-virtual-summit.html

Thanks