[merge request] Kubuntu Automation: exit nicer with non-existant commands with do-all

[José Manuel Santamaría Lema]

Hi Walter,

I have merged your fix for this just adding a small change on top of it:
https://git.launchpad.net/~kubuntu-packagers/+git/kubuntu-automation/commit/?
id=4c9d9afd7dc1e37ac506cab3d1fbcd112eeb4c17

Thank you! And sorry for taking so much time to get this simple bugfix in.