Fix CoAP adapter subtopics (#797)
Fix CoAP adapter subtopics (#797)

Remove `messages` part from the subtopics.

Signed-off-by: Dušan Borovčanin <678243bfa09a6ebf4a586bfa2057e53cece31497@mainflux.com>
drasko/mainflux,drasko/mainflux,drasko/mainflux,Mainflux/mainflux-lite