Changed max parallel downloads to 10

[hoang-himself]

@crramirez I'm not sure how likely this happens but fastestmirror=True connects to the mirror with the lowest ping instead of the highest bandwidth.

[crramirez]

Yes, so the latency is slower. Well I checked this article to understand well your change: https://ostechnix.com/how-to-speed-up-dnf-package-manager-in-fedora/ and they suggested also the fastesmirror