update_automation: more secure checks for git repo
update_automation: more secure checks for git repo

If the target directory was there but empty it was
still falsly recognized as git repo.
Remove the target directory before cloning to it,
it might already be there.

gosipyan/automation,gosipyan/automation,SUSE-Cloud/automation,gosipyan/automation,vmoravec/automation,aspiers/automation,vmoravec/automation,SUSE-Cloud/automation,aspiers/automation,aspiers/automation,vmoravec/automation,aspiers/automation,gosipyan/automation,SUSE-Cloud/automation,vmoravec/automation,SUSE-Cloud/automation