/set relay.network.allow_empty_password on
/set relay.network.password ""
Results in Lith not allowing you to connect, because it thinks you didn't configure your relay settings yet (since you left the password field empty)
Furthermore, if you already had a password set, you cannot change it to an empty one in the settings dialog. (Resetting it in Lith.conf manually again results in "Not configured" as mentioned above).