support 1.21.4
Update to 1.21
thanks to @snow2k9 for the port
Updated To Use 1.20.5 netwoking changes, Updated to Minecraft 1.20.5 Updated to Loom 1.6
tested with proxycommand 1.0 and 1.1 and velocity 3.2.0 SNAPSHOT build 360/velocity 3.3.0 SNAPSHOT build 389