fixed issue #3350 ,upgrade netty

pom.xml

@@ -301,7 +301,7 @@
             <dependency>
                 <groupId>io.netty</groupId>
                 <artifactId>netty-all</artifactId>
-                <version>4.1.6.Final</version>
+                <version>4.1.46.Final</version>
             </dependency>
             <dependency>
                 <groupId>org.jboss.netty</groupId>