Merge branch 'v4.0.6' into 'master'

build: update version.

See merge request public-server/server-sdk-java!26

Author: rongljz

README-CN.md

@@ -11,12 +11,12 @@ RongCloud IM Server SDK in Java.
     <dependency>
         <groupId>cn.rongcloud.im</groupId>
         <artifactId>server-sdk-java</artifactId>
-        <version>4.0.5</version>
+        <version>4.0.6</version>
     </dependency>
 ```
    * Gradle
 ```
-    compile group: 'cn.rongcloud.im', name: 'server-sdk-java', version: '4.0.5'
+    compile group: 'cn.rongcloud.im', name: 'server-sdk-java', version: '4.0.6'
    
 ```
    * 基于源码 Meavn 打包构建

README.md

@@ -10,12 +10,12 @@ RongCloud IM Server SDK in Java.
     <dependency>
         <groupId>cn.rongcloud.im</groupId>
         <artifactId>server-sdk-java</artifactId>
-        <version>4.0.5</version>
+        <version>4.0.6</version>
     </dependency>
 ```
 * Gradle
 ```
-    compile group: 'cn.rongcloud.im', name: 'server-sdk-java', version: '4.0.5'
+    compile group: 'cn.rongcloud.im', name: 'server-sdk-java', version: '4.0.6'
 ```
 * Build from source
 ```

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>cn.rongcloud.im</groupId>
     <artifactId>server-sdk-java</artifactId>
-    <version>4.0.5</version>
+    <version>4.0.6</version>
     <packaging>jar</packaging>
     <name>RongCloud IM Server SDK</name>
     <description>