fix http client credential problem

dumpling/export/config.go

@@ -8,7 +8,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
-	"net/http"
 	"regexp"
 	"strconv"
 	"strings"
@@ -21,11 +20,12 @@ import (
 	"github.com/pingcap/errors"
 	filter "github.com/pingcap/tidb-tools/pkg/table-filter"
 	"github.com/pingcap/tidb-tools/pkg/utils"
-	"github.com/pingcap/tidb/br/pkg/storage"
-	tcontext "github.com/pingcap/tidb/dumpling/context"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/spf13/pflag"
 	"go.uber.org/zap"
+
+	"github.com/pingcap/tidb/br/pkg/storage"
+	tcontext "github.com/pingcap/tidb/dumpling/context"
 )
 
 const (
@@ -531,21 +531,8 @@ func (conf *Config) createExternalStorage(ctx context.Context) (storage.External
 	if err != nil {
 		return nil, errors.Trace(err)
 	}
-	httpClient := http.DefaultClient
-	httpClient.Timeout = 30 * time.Second
-	maxIdleConnsPerHost := http.DefaultMaxIdleConnsPerHost
-	if conf.Threads > maxIdleConnsPerHost {
-		maxIdleConnsPerHost = conf.Threads
-	}
-	transport := http.DefaultTransport.(*http.Transport).Clone()
-	transport.MaxIdleConnsPerHost = maxIdleConnsPerHost
-	httpClient.Transport = transport
-
-	return storage.New(ctx, b, &storage.ExternalStorageOptions{
-		HTTPClient:      httpClient,
-		SkipCheckPath:   true,
-		SendCredentials: false,
-	})
+
+	return storage.New(ctx, b, &storage.ExternalStorageOptions{})
 }
 
 const (