Redeploying the bosh-lite director brakes existing deployment

[beyhan]

Steps to reproduce:

1. Follow the bosh-lite guide on https://bosh.io/docs/bosh-lite/ and deploy the bosh-lite director with the zookeeper release.
2. Make some changes to the bosh-lite director manifest.
3. Redeploy the bosh-lite director.
4. All zookeeper instances have agents in unresponsive state.