Ordinary database engine is deprecated but there is no simple mean to change database engine to Atomic for existing databases.

Possible options:
- ALTER DATABASE MODIFY ENGINE query.
- Flag that triggers migration at ClickHouse startup.

The latter should be easier to implement. 

{
    auto listen_hosts = DB::getMultipleValuesFromConfig(config, "", "listen_host");
    if (listen_hosts.empty())
    {
        listen_hosts.emplace_back("::1");
        listen_hosts.emplace_back("127.0.0.1");
    }
    return listen_hosts;
}
Strings getInterserverListenHosts(const Poco::Util::AbstractConfiguration & config)
{
    auto interserver_listen_hosts = DB::getMultipleValuesFromConfig(config, "", "interserver_listen_host");
    if (!interserver_listen_hosts.empty())
      return interserver_listen_hosts;
    
    return getListenHosts(config);
}
bool getListenTry(const Poco::Util::AbstractConfiguration & config)