当使用自定义的不安全的 registry 时，作业"docker.service/start"失败并显示"dependency"问题

Issue

• 在 OCP master 节点上尝试启动 docker.service 时，它会失败并显示以下错误消息：

  # systemctl start docker
  A dependency job for docker.service failed. See 'journalctl -xe' for details.
  

• registry.service 的状态有以下错误消息：

  # systemctl status registries
  [...]
  Feb 14 09:20:35 ocpmaster.example.com systemd[1]: Starting SystemWide Container Registries...
  Feb 14 09:20:35 ocpmaster.example.com registries[43156]: Unable to load and parse /etc/containers/registries.conf
  Feb 14 09:20:35 ocpmaster.example.com registries[43156]: .
  Feb 14 09:20:35 ocpmaster.example.com systemd[1]: registries.service: main process exited, code=exited, status=1/FAILURE
  Feb 14 09:20:35 ocpmaster.example.com systemd[1]: Failed to start SystemWide Container Registries.
  Feb 14 09:20:35 ocpmaster.example.com systemd[1]: Unit registries.service entered failed state.
  Feb 14 09:20:35 ocpmaster.example.com systemd[1]: registries.service failed.