currently the web server redirect me to mirrors#bfsu#edu#cn (Sorry, you can’t include links in your posts.) but it’s down now.
and open that URL it shows “We have detected enormous traffic from your network or client and have blocked your requests to ensure the quality of service for normal users.”
$ curl -v https://download.kde.org/stable/frameworks/5.116/portingAids/kdelibs4support-5.116.0.tar.xz
...
< location: https://mirrors.bfsu.edu.cn/kde/stable/frameworks/5.116/portingAids/kdelibs4support-5.116.0.tar.xz
...