Merge pull request #167 from yanghao605/1.8.0

[#119] bug fix, get service ports from env
diff --git a/proxy/cmd/cmd.go b/proxy/cmd/cmd.go
index 786dc59..d50f75f 100644
--- a/proxy/cmd/cmd.go
+++ b/proxy/cmd/cmd.go
@@ -61,7 +61,7 @@
 		},
 		cli.StringFlag{
 			Name:        "service-ports",
-			EnvVar:      common.EnvServicePorts,
+			EnvVar:      os.Getenv(common.EnvServicePorts),
 			Usage:       "service protocol and port,examples: --service-ports=http:3000,grpc:8000",
 			Destination: &Configs.LocalServicePorts,
 		},