Add deliveryMode parameter for AMQP notfication target (#4008)

Configuration migration was done.

Also adds documentation about AMQP configuration parameters.

Fixes #3982

docs/config/README.md

@@ -1,4 +1,4 @@
-# Minio Server `config.json` (v17) Guide [![Slack](https://slack.minio.io/slack?type=svg)](https://slack.minio.io) [![Go Report Card](https://goreportcard.com/badge/minio/minio)](https://goreportcard.com/report/minio/minio) [![Docker Pulls](https://img.shields.io/docker/pulls/minio/minio.svg?maxAge=604800)](https://hub.docker.com/r/minio/minio/) [![codecov](https://codecov.io/gh/minio/minio/branch/master/graph/badge.svg)](https://codecov.io/gh/minio/minio)
+# Minio Server `config.json` (v18) Guide [![Slack](https://slack.minio.io/slack?type=svg)](https://slack.minio.io) [![Go Report Card](https://goreportcard.com/badge/minio/minio)](https://goreportcard.com/report/minio/minio) [![Docker Pulls](https://img.shields.io/docker/pulls/minio/minio.svg?maxAge=604800)](https://hub.docker.com/r/minio/minio/) [![codecov](https://codecov.io/gh/minio/minio/branch/master/graph/badge.svg)](https://codecov.io/gh/minio/minio)
 
 Minio server stores all its configuration data in `${HOME}/.minio/config.json` file by default. Following sections provide detailed explanation of each fields and how to customize them. A complete example of `config.json` is available [here](https://raw.githubusercontent.com/minio/minio/master/docs/config/config.sample.json)
 

docs/config/config.sample.json

@@ -23,6 +23,7 @@
                 "exchange": "bucketevents",
                 "routingKey": "bucketlogs",
                 "exchangeType": "fanout",
+                "deliveryMode": 0,
                 "mandatory": false,
                 "immediate": false,
                 "durable": false,