Ohhh, sorry to mislead you but I assumed you had your user under "/home..."
Now I can see that you created the user on OMV and ticked the "home" button.
No worries, just go to the folder "docker-mosquitto" with cd /srv/dev-disk-by-uuid-e67cf220-d53c-4dfc-85db-41d8d6db235c/one/mike/docker-mosquitto
Then create the "mosquitto.conf" with:
nano mosquitto/config/mosquitto.conf
Copy/Paste what I told you on #38
Now change the command of docker to:
docker run -it --name mosquitto -p 1883:1883 -v $(pwd)/mosquitto/config:/mosquitto/config/ -v $(pwd)/mosquitto/data:/mosquitto/data/ -v $(pwd)/mosquitto/log:/mosquitto/log/ eclipse-mosquitto