Currently, IRollbar defines the Config property of the RollbarConfig type. All the RollbarConfig properties are editable. This creates an unintended loophole for a misleading "reconfiguration" of the logger, that is expecting the operationally critical properties to be reconfigured only via IRollbar.Configure(RollbarConfig newConfig) call. Let's close the loophole and prevent potential misuse of the Notifier API.