Code review comment for lp:~gandelman-a/charms/precise/rabbitmq-server/cluster_fix

I've reverted the charm's peer relations back to their previous behavior. Turns out, when clustering peers, rabbitmq needs to address its peers by the peers' node name, which is the local hostname of that system. Using anything else (IP, FQDN, CNAME) wont work. This is why the original hook passed output of `hostname` across the relation as the hostname and did not use anything from the provider. I've tested on both the EC2 and OSAPI provider and clustering works as expected.