RabbitMQ messenger support (#2874)

bungee/build.gradle

@@ -39,6 +39,7 @@ shadowJar {
     relocate 'com.mongodb', 'me.lucko.luckperms.lib.mongodb'
     relocate 'org.bson', 'me.lucko.luckperms.lib.bson'
     relocate 'redis.clients.jedis', 'me.lucko.luckperms.lib.jedis'
+    relocate 'com.rabbitmq', 'me.lucko.luckperms.lib.rabbitmq'
     relocate 'org.apache.commons.pool2', 'me.lucko.luckperms.lib.commonspool2'
     relocate 'ninja.leaping.configurate', 'me.lucko.luckperms.lib.configurate'
 }

bungee/src/main/resources/config.yml

@@ -221,6 +221,8 @@ watch-files: true
 #                    configured below.
 #   => redisbungee   Uses Redis pub-sub to push changes, using the RedisBungee API. You need to have
 #                    the RedisBungee plugin installed.
+#   => rabbitmq      Uses RabbitMQ pub-sub to push changes. Your server connection info must be
+#                    configured below.
 #   => auto          Attempts to automatically setup a messaging service using redis or sql.
 messaging-service: auto
 
@@ -244,6 +246,14 @@ redis:
   address: localhost
   password: ''
 
+# Settings for RabbitMQ.
+# Port 5672 is used by default; set address to "host:port" if differs
+rabbitmq:
+  enabled: false
+  address: localhost
+  username: 'guest'
+  password: 'guest'
+