abstract_replication_strategy: Make calculate_natural_endpoints public
abstract_replication_strategy: Make calculate_natural_endpoints public

It is used by storage_service.

scylladb/scylla,raphaelsc/scylla,raphaelsc/scylla,kjniemi/scylla,kjniemi/scylla,avikivity/scylla,kjniemi/scylla,duarten/scylla,avikivity/scylla,duarten/scylla,avikivity/scylla,raphaelsc/scylla,scylladb/scylla,duarten/scylla,scylladb/scylla,scylladb/scylla