Update message.md

Andor233 · web-flow · commit f0764797d648 · 2020-07-17T10:25:59.000+08:00
Add code block ending
diff --git a/docs/message.md b/docs/message.md
@@ -174,3 +174,4 @@ Server sending
 Client received 2 frames
 Frame=From
 Frame=Server
+```
