Make system output look less bloated.

main.go

@@ -145,8 +145,8 @@ func main() {
 	case *flagVersion:
 		// If requested, show version and quit.
 		fmt.Println("Go-sendxmpp", version)
-		fmt.Println("System:", runtime.GOOS, "/", runtime.GOARCH, "/",
-			runtime.Version())
+		system := runtime.GOOS + "/" + runtime.GOARCH
+		fmt.Println("System:", system, runtime.Version())
 		fmt.Println("License: BSD-2-clause")
 		os.Exit(0)
 		// Quit if Ox (OpenPGP for XMPP) is requested for unsupported operations like