Changing the bastion count from 1 to 2 destroys existing cluster

[MaartenKreuger]

When the cluster is deployed using terraform with a single bastion host, and the count is then changed to two bastions, all bastions, masters, and worker nodes are deleted and redeployed, wiping the existing cluster.

This is unexpected behaviour. If this change cannot be performed on an existing cluster, it should be ignored.