Fix addons block
Fix addons block

https://bosh.io/docs/runtime-config/#placement-rules
Signed-off-by: Leah Hanson <59915d4d5a651c1df4fd522b917423b47c84f68b@pivotal.io>

jaimegag/kubo-deployment,pivotal-cf-experimental/kubo-deployment,pivotal-cf-experimental/kubo-deployment,jaimegag/kubo-deployment