bugfix
bugfix

Do not acknowledge responses to NON-confirmable requests, instead response
is NON-confirmable as well.

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