retry redirect to AlreadyVisitedUrl will loop error

[Shinku-Chen]

func TestRedirectErrorRetry(t *testing.T) {
	ts := newTestServer()
	defer ts.Close()
	c := NewCollector()
	c.OnError(func(r *Response, err error) {
		if r.Ctx.Get("notFirst") == "" {
			r.Ctx.Put("notFirst", "first")
			_ = r.Request.Retry()
			return
		}
		t.Error("loop")
	})
	c.OnResponse(func(response *Response) {
		println(1)
	})
	c.Visit(ts.URL + "/redirected/")
	c.Visit(ts.URL + "/redirect")
}

[Shinku-Chen]

add config

c.OnError(func(response *colly.Response, err error) {
var alreadyVisitedError *colly.AlreadyVisitedError
if errors.As(err, &alreadyVisitedError) {
response.Request.URL = &url.URL{} //防止在retry的时候出现已经访问的错误
}
})

to forbidden retry a Visited url