fix stats output alignment

[anysql]

Values are rounded in Printf

func main() {
fmt.Printf("99.9 = %4.1f\n", 99.9) // 99.9
fmt.Printf("99.949 = %4.1f\n", 99.949) // 99.9
fmt.Printf("99.950 = %4.1f\n", 99.950) // 100.0
fmt.Printf("99.99 = %4.1f\n", 99.99) // 100.0
}

[zhijian-pro]

The impact of this is not important, but it will make the code look very strange, I do not recommend it.