change default value for host arg

main.go

@@ -24,7 +24,7 @@ import (
 var webOutput embed.FS
 
 var (
-	hostname = flag.String("H", "localhost", "server http address")
+	hostname = flag.String("H", "", "server http address")
 	port     = flag.Int("p", 5000, "server http port")
 )
 
@@ -410,7 +410,7 @@ func main() {
 	})
 
 	addr := fmt.Sprintf("%s:%d", *hostname, *port)
-	fmt.Printf("starting http server on http://%s\n", addr)
+	fmt.Printf("starting http server on %s\n", addr)
 	if err := http.ListenAndServe(addr, mux); err != nil {
 		log.Fatalf("failed to start http server: %v\n", err)
 	}