examples/asymcute_mqttsn: adapt to API change
examples/asymcute_mqttsn: adapt to API change

jasonatran/RIOT,miri64/RIOT,ant9000/RIOT,OTAkeys/RIOT,kYc0o/RIOT,OlegHahm/RIOT,jasonatran/RIOT,kaspar030/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,OlegHahm/RIOT,authmillenon/RIOT,kYc0o/RIOT,miri64/RIOT,authmillenon/RIOT,jasonatran/RIOT,authmillenon/RIOT,miri64/RIOT,kYc0o/RIOT,kYc0o/RIOT,kaspar030/RIOT,ant9000/RIOT,kaspar030/RIOT,jasonatran/RIOT,authmillenon/RIOT,kYc0o/RIOT,ant9000/RIOT,ant9000/RIOT,jasonatran/RIOT,miri64/RIOT,kaspar030/RIOT,OTAkeys/RIOT,OTAkeys/RIOT,authmillenon/RIOT,ant9000/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,miri64/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT