Incorrect error returned if a backup has not yet been created.

[brendan-stephens]

What happened?

Using avn service wait to check for state, a call to create a remote replica failed with the following error.

ERROR   command failed: Error: {"errors":[{"message":"Creation of a read replica not allowed under current plan","status":403}],"message":"Creation of a read replica not allowed under current plan"}

What did you expect to happen?

I believe this may be timing/race between service available and backup exists to create the replica, but the error message should be updated.

ERROR   command failed: Error: {"errors":[{"message":"Creation of a read replica not allowed when a backup is unavailable","status":400}]...