Added configuration option to change the probe's listen address.

Change-Id: I7e8aa7bf4a4756f12211e7108cabcdc86aacd78a
diff --git a/rw_core/main.go b/rw_core/main.go
index 6f06576..2311029 100644
--- a/rw_core/main.go
+++ b/rw_core/main.go
@@ -276,7 +276,7 @@
 	 * objects there can be a single probe end point for the process.
 	 */
 	p := &probe.Probe{}
-	go p.ListenAndServe(rw.config.ProbePort)
+	go p.ListenAndServe(fmt.Sprintf("%s:%d", rw.config.ProbeHost, rw.config.ProbePort))
 
 	// Add the probe to the context to pass to all the services started
 	probeCtx := context.WithValue(ctx, probe.ProbeContextKey, p)