Update amqplib to v0.4.1

(Same as issue "Update amqplib to v0.4.0 #24) but later :
Change dependency into 0.4.1 ( or maybe 0.4.x for next time)
as only amqplib is 0.4.1 allows Node 5 :
{
"name": "amqplib",
"homepage": "http://squaremo.github.io/amqp.node/",
"main": "./channel_api.js",
"version": "0.4.1",
"description": "An AMQP 0-9-1 (e.g., RabbitMQ) library and client.",
"repository": {
"type": "git",
"url": "https://github.com/squaremo/amqp.node.git"
},
"engines": {
"node": ">=0.8 <5 || ^5"
},

As Cloud foundry (Bluemix) uses now a Node 5.2.0, we cannot use jackrabbit ->amqp 0.4.0->node <5

thanks