Fix deregister server event test
Fix deregister server event test

DavidAntliff/AwaLWM2M,DavidAntliff/AwaLWM2M,DavidAntliff/AwaLWM2M,FlowM2M/AwaLWM2M,DavidAntliff/AwaLWM2M,FlowM2M/AwaLWM2M,FlowM2M/AwaLWM2M,FlowM2M/AwaLWM2M