gdm-systemd from home:yfjiang:branches:GNOME:Factory project

需要 openSUSE Factory ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:yfjiang:branches:GNOME:Factory/openSUSE_Factory/home:yfjiang:branches:GNOME:Factory.repo
zypper refresh
zypper install gdm-systemd