i2pd from home:ol project

需要 CentOS 8 ，用 root 執行：

cd /etc/yum.repos.d/
wget https://download.opensuse.org/repositories/home:ol/CentOS_8/home:ol.repo
yum install i2pd

需要 CentOS 7 ，用 root 執行：

cd /etc/yum.repos.d/
wget https://download.opensuse.org/repositories/home:ol/CentOS_7/home:ol.repo
yum install i2pd

需要 Mageia 8 ，用 root 執行：

dnf config-manager --add-repo https://download.opensuse.org/repositories/home:ol/Mageia_8/home:ol.repo
dnf install i2pd