h4/slave/D,N(payload D = name of other H4 device on the network, N=1 => add slave; 0 => remove slave). Added only if H4P_AsyncMQTT loaded
h4/slave/D,N (payload D = name of other H4 device on the network, N=1 => add slave; 0 => remove slave). Added only if H4P_AsyncMQTT loaded