Main error
Wrong location.
If you bash into the container like this, you can look around.
docker exec -it openhab bash
You can see that the “userdata” folder is located at
/openhab/userdata/backup/
docker exec -it openhab runtime/bin/restore /openhab/userdata/backup/OHRunBackup.zip
Now a little “rant” 
Why do you sudo docker? Add the docker group to your user.
See:
sudo usermod -a -G docker myUserName
EDIT
Oh an btw, thread hijacking is not nice! 
Please read the following topic: