notification-manager: host messages are trimmed wrongly

[foxriver76]

https://github.com/iobroker-community-adapters/ioBroker.email/blob/6f6f1e56a06e3afd083ce29da8edf6a2230a7ac5/main.js#L96 instance can be a host too detect if starts with system.adapter or system.host and use substring or use everything after second dot. ;-)