Update to Netty 4.2.x

[DerGuteMoritz]

See https://github.com/netty/netty/wiki/Netty-4.2-Migration-Guide

[ieugen]

Netty 4.2.x can use new JDK native access and avoid depending on Unsafe, which is deprecated and scheduled to be removed : https://netty.io/wiki/java-24-and-sun.misc.unsafe.html

WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
WARNING: sun.misc.Unsafe::objectFieldOffset has been called by io.netty.util.internal.PlatformDependent0$3 (file:/home/ieugen/.m2/repository/io/netty/netty-common/4.1.65.Final/netty-common-4.1.65.Final.jar)