update readme

README.md

@@ -25,47 +25,47 @@ java 6+ && netty 4 && protobuf 2.5.0
 <dependency>
     <groupId>com.baidu</groupId>
     <artifactId>brpc-java</artifactId>
-    <version>2.5.8</version>
+    <version>2.5.9</version>
 </dependency>
 ```
 Spring环境：
 ```xml
 <dependency>
     <groupId>com.baidu</groupId>
     <artifactId>brpc-spring</artifactId>
-    <version>2.5.8</version>
+    <version>2.5.9</version>
 </dependency>
 ```
 SpringBoot环境：
 ```xml
 <dependency>
     <groupId>com.baidu</groupId>
     <artifactId>brpc-spring-boot-starter</artifactId>
-    <version>2.5.8</version>
+    <version>2.5.9</version>
 </dependency>
 ```
 SpringCloud环境：
 ```xml
 <dependency>
     <groupId>com.baidu</groupId>
     <artifactId>spring-cloud-brpc</artifactId>
-    <version>2.5.8</version>
+    <version>2.5.9</version>
 </dependency>
 ```
 Zookeeper注册中心：
 ```xml
 <dependency>
     <groupId>com.baidu</groupId>
     <artifactId>brpc-java-naming-zookeeper</artifactId>
-    <version>2.5.8</version>
+    <version>2.5.9</version>
 </dependency>
 ```
 Consul注册中心：
 ```xml
 <dependency>
     <groupId>com.baidu</groupId>
     <artifactId>brpc-java-naming-consul</artifactId>
-    <version>2.5.8</version>
+    <version>2.5.9</version>
 </dependency>
 ```
 ### Server端使用