Endpoint model maps to JSON property fqdm

In the [model](https://github.com/secureCodeBox/defectdojo-client-java/blob/67f9f52ee60b38804fa21bf3058ab56d78fca266/src/main/java/io/securecodebox/persistence/defectdojo/model/Endpoint.java#L29) we map the JSON property `fqdm`, which seems to be wrong. Typically full qualified domain name is abbreviated "fqdn".