Remove World Leave Message

I found it really annoying that you can toggle the join message, but not the leave message, so I made a little transformer using ASM and stuffed it inside a so called Early Plugin.

Drop the JAR-file inside "earlyplugins"-folder, and either use --accept-early-plugins argument or press ENTER when the console prompts you to.

Sidenote! Unsure why the file had to be a ZIP-file; either way, it's a JAR file in the releases under the Github repository, if you want to save a step on extracting the file.