SDB Talk:DNF

If I run `zypper in PackageKit-backend-dnf` zypper notices a conflict and forces me to remove the current PackageKit backend before proceeding to install the dnf backend. Having done this `dnf swap PackageKit-backend-zypp PackageKit-backend-dnf` just results in error.

If I just run `dnf swap PackageKit-backend-zypp PackageKit-backend-dnf` it will remove the old and install the new backend in one step.

The documentation could be more clear about this.