I was getting also error when starting the OH under docker swarm with multiple overlay networks. OH choses the wrong network and interface.
The value can not be set through paper ui, as the suggestions are wrong.
Editing /var/lib/openhab2/config/org/eclipse/smarthome/network.config and setting
broadcastAddress="192.168.3.255" --> broadcast address
primaryAddress="192.168.3.0/24" --> subnet address
removes the warning of multiple address and the right interface is selected.
Running this thread for further findings arroung docker swarm environment:
Deploying OH 2.4.0 to docker swarm