docs: remove redundant asterisk in example

remove redundant asterisk in example

doc.go

@@ -21,7 +21,7 @@ them in their own goroutines.
 	c := cron.New()
 	c.AddFunc("30 * * * *", func() { fmt.Println("Every hour on the half hour") })
 	c.AddFunc("30 3-6,20-23 * * *", func() { fmt.Println(".. in the range 3-6am, 8-11pm") })
-	c.AddFunc("CRON_TZ=Asia/Tokyo 30 04 * * * *", func() { fmt.Println("Runs at 04:30 Tokyo time every day") })
+	c.AddFunc("CRON_TZ=Asia/Tokyo 30 04 * * *", func() { fmt.Println("Runs at 04:30 Tokyo time every day") })
 	c.AddFunc("@hourly",      func() { fmt.Println("Every hour, starting an hour from now") })
 	c.AddFunc("@every 1h30m", func() { fmt.Println("Every hour thirty, starting an hour thirty from now") })
 	c.Start()