Free DTLS sessions when shutting down
Free DTLS sessions when shutting down

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