Support passive queue declaration in amqp_consumer (#5831)

plugins/outputs/amqp/README.md

@@ -33,7 +33,7 @@ For an introduction to AMQP see:
   # exchange_type = "topic"
 
   ## If true, exchange will be passively declared.
-  # exchange_declare_passive = false
+  # exchange_passive = false
 
   ## Exchange durability can be either "transient" or "durable".
   # exchange_durability = "durable"

plugins/outputs/amqp/amqp.go

@@ -92,7 +92,7 @@ var sampleConfig = `
   # exchange_type = "topic"
 
   ## If true, exchange will be passively declared.
-  # exchange_declare_passive = false
+  # exchange_passive = false
 
   ## Exchange durability can be either "transient" or "durable".
   # exchange_durability = "durable"

plugins/outputs/amqp/client.go

@@ -78,6 +78,10 @@ func Connect(config *ClientConfig) (*client, error) {
 }
 
 func (c *client) DeclareExchange() error {
+	if c.config.exchange == "" {
+		return nil
+	}
+
 	var err error
 	if c.config.exchangePassive {
 		err = c.channel.ExchangeDeclarePassive(