CentOS6目前还可用的源-腾讯源（20200129亲测可用，记录）
Linux：CentOS 6.8今日yum安装时，出现如下错误：[root@localhost ~]# yum -y install treeLoaded plugins: fastestmirrorSetting up Install ProcessDetermining fastest mirrorsYumRepo Error: All mirror URLs are not using ftp, http[s] or file. Eg. Invalid release/repo/arch
