Disable listening on port 30303 for the canary (#1198)

cmd/mailserver-canary/main.go

@@ -206,6 +206,7 @@ func makeNodeConfig() (*params.NodeConfig, error) {
 		nodeConfig.LogFile = *logFile
 	}
 
+	nodeConfig.ListenAddr = ""
 	nodeConfig.NoDiscovery = true
 
 	return whisperConfig(nodeConfig)

node/node.go

@@ -82,6 +82,8 @@ func MakeNode(config *params.NodeConfig, db *leveldb.DB) (*node.Node, error) {
 			return nil, fmt.Errorf("%v: %v", ErrLightEthRegistrationFailureUpstreamEnabled, err)
 		}
 
+		logger.Info("LES protocol is disabled")
+
 		// `personal_sign` and `personal_ecRecover` methods are important to
 		// keep DApps working.
 		// Usually, they are provided by an ETH or a LES service, but when using