Fix defect IOTCLT-488 - Resource observation notifications always have content-type 99
Fix defect IOTCLT-488 - Resource observation notifications always have content-type 99

tridonic-com/mbed-client,ARMmbed/mbed-client,tridonic-com/mbed-client,ARMmbed/mbed-client,ARMmbed/mbed-client,tridonic-com/mbed-client