Notification if HiveMQ starts without Security Extension in CE

[dobermai]

Acceptance Criteria:

• Notification occurs if HiveMQ has been started without security extension

• Notification doesn't occur if HiveMQ has been starten with security extension

• The notification is big and can't be overseen

• The notification occurs at HiveMQ start up

• If this notification occurs HiveMQ can be stopped immediately

[SgtSilvio]

• If this notification occurs HiveMQ can be stopped immediately

With #126 no clients can connect if no security extension is present. So HiveMQ can be safely stopped without creating a time window where unauthenticated clients can connect.