all mirror urls are not using ftp http s or file. centos 6 cmd code example
Example: YumRepo Error: All mirror URLs are not using ftp, http[s] or file. Eg. Invalid release/repo/arch combination/
echo "http://vault.centos.org/5.11/os/x86_64/" > /var/cache/yum/base/mirrorlist.txt
echo "http://vault.centos.org/5.11/extras/x86_64/" > /var/cache/yum/extras/mirrorlist.txt
echo "http://vault.centos.org/5.11/updates/x86_64/" > /var/cache/yum/updates/mirrorlist.txt
try use the centos 7