bugfix: return unknown critical option in payload
bugfix: return unknown critical option in payload

joaopedrotaveira/libcoap,alexaring/libcoap,authmillenon/libcoap,gebart/libcoap,thecodemaiden/libcoap-fork,markushx/libcoap,fredericgermain/libcoap,gebart/libcoap,OlegHahm/libcoap,RIOT-OS/libcoap,joaopedrotaveira/libcoap,alexaring/libcoap,markushx/libcoap,pabigot/libcoap,sgso/libcoap,OlegHahm/libcoap,thecodemaiden/libcoap-fork,alexaring/libcoap,RIOT-OS/libcoap,gebart/libcoap,fredericgermain/libcoap,nmacs/libcoap,OlegHahm/libcoap,sgso/libcoap,fredericgermain/libcoap,authmillenon/libcoap,pabigot/libcoap,sgso/libcoap,nmacs/libcoap,PolymorhicCode/libcoap,authmillenon/libcoap,markushx/libcoap,nmacs/libcoap,pabigot/libcoap,joaopedrotaveira/libcoap