Return the response directly if it's a options PreflightHeader request

1.4.1 released

type Test struct {
    Date    time.Time    `form:"Date, 2006-01-02"`
    Save    bool            `form:"Save"`
}

add config ListenTCP4

when user want to listen on the TCP4, because now almost use the ipv4.
but default lister on the ipv6

This reverts commit ddbfc25e.

This reverts commit 1f268526.