Amazon ECS cluster provider fails with AWS error

[dariussantaras]

When using the ECS cluster provider as documented here https://proto.actor/docs/cluster/aws-provider-net/ it fails with an error in AWS when calling ECS API:

Amazon.ECS.Model.InvalidParameterException: Invalid identifier: Identifier is for cluster ChatServer. Your cluster is default

Also, the ECS polling interval is not based on seconds as the config parameter name suggests (PollIntervalSeconds)