Plugin Messaging fix

Added a secret key within the plugin messaging method to prevent client-side abuse.

Setup

Add a secret key to your configs:
(Make sure these are the same on both proxy & bukkit instances)

Under bukkit:
pluginMessaging:
channel: nuvotifier:votes
secret: examplesecret

Under bungee:
pluginMessaging:
channel: nuvotifier:votes
secret: examplesecret

Under velocity:
[forwarding.pluginMessaging]
channel = "nuvotifier:votes"
secret = "examplesecret"