将InsecureSkipVerify与Appengine一起使用时出错

Question

I am trying to use the InsecureSkipVerify: true parameter together with the appengine but the following error appears when executing the dev_appserver.py app.yaml code:

ERROR 2019-02-02 16:44:49,039 http_runtime.py:420] bad runtime process port ['']

panic: interface conversion: http.RoundTripper is init.failingTransport, not *http.Transport

The port being already built into appengine.Main()

How could I then use InsecureSkipVerify together with appengine?

app.yaml

runtime: go
api_version: go1

handlers:
- url: /.*
  script: _go_app

main.go

package main

import (
    "encoding/json"
    "github.com/gorilla/mux"
    "net/http"
    "google.golang.org/appengine"
    "crypto/tls"
)

type Foo struct {
    Text string `json:"text"`
}

func GetInfo(w http.ResponseWriter, r *http.Request) {
    json.NewEncoder(w).Encode(Foo{"hello"})
}

func init(){
    r := mux.NewRouter()
    r.HandleFunc("/sample", GetInfo)
    http.DefaultTransport.(*http.Transport).TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
    http.Handle("/", r)
}

func main() {
    appengine.Main()
}