Upgrade Netty 4.0.20 and Javassist 3.18.2

Author: Stephane Landelle

providers/netty/pom.xml

@@ -39,12 +39,12 @@
         <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-all</artifactId>
-            <version>4.0.19.Final</version>
+            <version>4.0.20.Final</version>
         </dependency>
         <dependency>
             <groupId>org.javassist</groupId>
             <artifactId>javassist</artifactId>
-            <version>3.18.1-GA</version>
+            <version>3.18.2-GA</version>
         </dependency>
     </dependencies>