added description to the rabbitmq max_poll_messages property

application/src/main/resources/thingsboard.yml

@@ -1658,6 +1658,7 @@ queue:
     connection_timeout: "${TB_QUEUE_RABBIT_MQ_CONNECTION_TIMEOUT:60000}"
     # RabbitMQ has a timeout for connection handshake. When clients run in heavily constrained environments, it may be necessary to increase the timeout
     handshake_timeout: "${TB_QUEUE_RABBIT_MQ_HANDSHAKE_TIMEOUT:10000}"
+    # The maximum number of messages returned in a single call of doPoll() method
     max_poll_messages: "${TB_QUEUE_RABBIT_MQ_MAX_POLL_MESSAGES:1}"
     queue-properties:
       # RabbitMQ properties for Rule Engine queues