update readme, for start grpc server and client

funasr/runtime/python/grpc/Readme.md

@@ -11,6 +11,11 @@ python -m grpc_tools.protoc  --proto_path=./proto -I ./proto    --python_out=. -
 ```
 
 Step 2) start grpc server
+```
+python grpc_main_server.py --port 10095
+```
 
-
-Step 3) start grpc client
+Step 3) start grpc client
+```
+python grpc_main_client_mic.py --host 127.0.0.1 --port 10095
+```

funasr/runtime/python/grpc/grpc_main_server.py

@@ -20,6 +20,7 @@ if __name__ == '__main__':
     parser.add_argument("--port",
                         type=int,
                         default=10095,
+                        required=True,
                         help="grpc server port")
                         
     parser.add_argument("--user_allowed",