builder/openstack: fix issue 5575 - support shutdown by Sysprep
builder/openstack: fix issue 5575 - support shutdown by Sysprep

timsutton/packer,paulmey/packer,grubernaut/packer,timsutton/packer,grubernaut/packer,rnaveiras/packer,mitchellh/packer,rnaveiras/packer,hashicorp/packer,pecigonzalo/packer,hashicorp/packer,paulmey/packer,timsutton/packer,mitchellh/packer,ricardclau/packer,dave2/packer,paulmey/packer,hashicorp/packer,grubernaut/packer,ricardclau/packer,dave2/packer,dave2/packer,paulmey/packer,ricardclau/packer,timsutton/packer,paulmey/packer,grubernaut/packer,mitchellh/packer,rnaveiras/packer,pecigonzalo/packer,paulmey/packer,timsutton/packer,rnaveiras/packer,grubernaut/packer,mitchellh/packer,grubernaut/packer,ricardclau/packer,hashicorp/packer,dave2/packer,pecigonzalo/packer,timsutton/packer,rnaveiras/packer,ricardclau/packer,mitchellh/packer,rnaveiras/packer,ricardclau/packer,pecigonzalo/packer,dave2/packer,dave2/packer