Credentials returned after registering an app are hard coded, which causes problems if RabbitMQ is not hosted on localhost

Description

The method controller/app/Service.go/createNewApp always returns "amqp://guest:guest@127.0.0.1:5672" as credentials for an App registering to the Event System. This needs to be fixed.

Expected Behavior

Method returns correct crededentials dynamically.

Actual Behavior

Hard coded string that worked until it didn't 🤷

Possible Fix

Use data read from the config file and stored in global vars in config package, e.g. config.AMQPHost.