fix race condition in hooks
fix race condition in hooks

timsutton/packer,bryson/packer,mitchellh/packer,tas50/packer,dave2/packer,pecigonzalo/packer,grubernaut/packer,dave2/packer,dave2/packer,hashicorp/packer,tas50/packer,rnaveiras/packer,timsutton/packer,dave2/packer,paulmey/packer,ricardclau/packer,bryson/packer,tas50/packer,mitchellh/packer,grubernaut/packer,grubernaut/packer,paulmey/packer,hashicorp/packer,ricardclau/packer,mitchellh/packer,rnaveiras/packer,paulmey/packer,paulmey/packer,ricardclau/packer,hashicorp/packer,hashicorp/packer,rnaveiras/packer,tas50/packer,ricardclau/packer,dave2/packer,rnaveiras/packer,rnaveiras/packer,grubernaut/packer,timsutton/packer,mitchellh/packer,bryson/packer,pecigonzalo/packer,paulmey/packer,grubernaut/packer,tas50/packer,timsutton/packer,bryson/packer,timsutton/packer,bryson/packer,pecigonzalo/packer,pecigonzalo/packer,tas50/packer,rnaveiras/packer,ricardclau/packer,ricardclau/packer,dave2/packer,grubernaut/packer,paulmey/packer,timsutton/packer,mitchellh/packer,bryson/packer