fixed broken bit mask
fixed broken bit mask

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