fix cty bool passing for provisioners, too
fix cty bool passing for provisioners, too

rnaveiras/packer,mitchellh/packer,ricardclau/packer,hashicorp/packer,mitchellh/packer,hashicorp/packer,mitchellh/packer,hashicorp/packer,hashicorp/packer,rnaveiras/packer,ricardclau/packer,pecigonzalo/packer,pecigonzalo/packer,mitchellh/packer,rnaveiras/packer,pecigonzalo/packer,ricardclau/packer,ricardclau/packer,rnaveiras/packer,mitchellh/packer,rnaveiras/packer,pecigonzalo/packer,rnaveiras/packer,ricardclau/packer,ricardclau/packer