Incorrect cloud provider type for OpenStack terraform template

[a-anokhin]

launchpad/examples/terraform/openstack/output.tf

Lines 62 to 65 in ca0e887

	cloud = {
	provider = "openstack"
	configFile = var.provider_config_file_path
	}

openstack is unsupported cloud provider type.
Tested with launchpad 1.5.2 and receive error
level=error msg="invalid Kubernetes config: cloud provider value must be one of [aws azure vsphere gce external]

For OpenStack provider should be external

cloud = {
    provider = "external"
    configFile = var.provider_config_file_path
}