1、增加TCP连接过程打印，以便查看连接失败原因

sec-beidou-fwd/src/main/java/com/imdroid/beidou_fwd/service/TCPClient.java

@@ -73,6 +73,10 @@ public class TCPClient {
                             }
                         }, 5000, TimeUnit.MILLISECONDS);
                     } else {
+                        future.channel().config().setWriteBufferWaterMark(new WriteBufferWaterMark(
+                                1024 * 1024,   // low
+                                4 *1024*1024    // high
+                        ));
                         logger.info("{}:{} tcp client start success!",host,port);
                     }
                 }