Fix for AsyncHttpClient#51 Bump Netty version to 3.3.1

Author: jfarcand

pom.xml

@@ -61,7 +61,7 @@
         <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty</artifactId>
-            <version>3.3.0.Final</version>
+            <version>3.3.1.Final</version>
             <exclusions>
                 <exclusion>
                     <groupId>javax.servlet</groupId>