Systemd service ldconfig.service is broken

```
[systemd]
Failed Units: 1
  ldconfig.service
```

The systemd service `ldconfig.service` fails because `ldconfig` is used during image creation and there seems to be a permission problem at runtime:
Log: `localhost ldconfig[1276]: /sbin/ldconfig: Renaming of /etc/ld.so.cache~ to /etc/ld.so.cache failed: Permission denied`

As a quick solution, the `ldconfig.service` could be removed.