OptionalcertThe generated/loaded TLS certificate set, when SERVER_TLS was enabled.
Started origin clients, tunnels, and bound listener addresses in the
same order as the enabled listener entries in CLIENTS.
OptionalserverThe relay server, if one was started by this call.
Started target clients and tunnels in the same order as the enabled
dialer entries in CLIENTS.
Result returned by StartRelayProxyCore / StartRelayProxy.