GraphtieReporter initialized via reporter-config cannot follow DNS changes

[ngrigoriev]

From what I see in the code (and what I observed today in our applications), GraphiteReporterConfig calls the constructor of Graphite class that forces it to stick to Graphite server address resolved at startup. Even if DNS information changes, the application won't be able to follow the change.

build(new Graphite(new InetSocketAddress(hostPort.getHost(),
                        hostPort.getPort())));

I think it should call public Graphite(String hostname, int port) instead.