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

Change-Id: I7e8aa7bf4a4756f12211e7108cabcdc86aacd78a
diff --git a/common/probe/probe.go b/common/probe/probe.go
index fdb07e8..8a8e485 100644
--- a/common/probe/probe.go
+++ b/common/probe/probe.go
@@ -207,7 +207,7 @@
 }
 
 // ListenAndServe implements 3 HTTP endpoints on the given port for healthz, readz, and detailz. Returns only on error
-func (p *Probe) ListenAndServe(port int) {
+func (p *Probe) ListenAndServe(address string) {
 	mux := http.NewServeMux()
 
 	// Returns the result of the readyFunc calculation
@@ -219,7 +219,7 @@
 	// Returns the details of the services and their status as JSON
 	mux.HandleFunc("/detailz", p.detailzFunc)
 	s := &http.Server{
-		Addr:    fmt.Sprintf(":%d", port),
+		Addr:    address,
 		Handler: mux,
 	}
 	log.Fatal(s.ListenAndServe())