Wrap exchangeDeclare with conditional rather than queueBind

I was trying to convince river-rabbitmq not to declare the exchange it was connecting to (because one side was declaring it as direct and the other as fanout, and I was hacking around trying to fix it), but not having any luck.

Checking out the code, I suspect the if statement avoiding declaring the exchange it wrapping the wrong method, so I've tweaked it. I'm not a Java developer, nor am I terribly familiar with RabbitMQ's API, nor have I even tried my fix, so I might be talking nonsense!

But I thought I'd highlight it just in case...