fix plugin config

plugins/emqttd_auth_mysql/README.md

@@ -1,11 +1,11 @@
-##  Overview
+
+## Overview
 
 Authentication with user table of MySQL database.
 
 ## etc/plugin.config
 
-```erlang
-[
+```
  {emysql, [
     {pool,      4},
     {host,      "localhost"},
@@ -24,7 +24,6 @@ Authentication with user table of MySQL database.
         {password, password}
     ]}
  ]}
-].
 ```
 
 ## Users Table(Demo)

plugins/emqttd_auth_mysql/etc/plugin.config

@@ -1,18 +1,16 @@
-[
- {emysql, [
-    {pool,      4},
-    {host,      "localhost"},
-    {port,      3306},
-    {username,  "root"}, 
-    {password,  "public"},
-    {database,  "mqtt"},
-    {encoding,  utf8}
- ]},
- {emqttd_auth_mysql, [
-    {users_table, mqtt_users},
-    {field_mapper, [
-        {username, username},
-        {password, password, plain}
-    ]}
- ]}
-].
+{emysql, [
+   {pool,      4},
+   {host,      "localhost"},
+   {port,      3306},
+   {username,  "root"},
+   {password,  "public"},
+   {database,  "mqtt"},
+   {encoding,  utf8}
+]},
+{emqttd_auth_mysql, [
+   {users_table, mqtt_users},
+   {field_mapper, [
+       {username, username},
+       {password, password, plain}
+   ]}
+]}