Remove NetworkService::config() (#8653)

whisper/cli/src/main.rs

@@ -218,7 +218,7 @@ fn execute<S, I>(command: I) -> Result<(), Error> where I: IntoIterator<Item=S>,
 	let network = devp2p::NetworkService::new(net::NetworkConfiguration::new_local(), None)?;
 
 	// Start network service
-	network.start()?;
+	network.start().map_err(|(err, _)| err)?;
 
 	// Attach whisper protocol to the network service
 	network.register_protocol(whisper_network_handler.clone(), whisper::net::PROTOCOL_ID,