php7-gd from home:emendonca:php73 project

需要 SLE 12 SP5 ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:emendonca:php73/SLE_12_SP5/home:emendonca:php73.repo
zypper refresh
zypper install php7-gd