config: remove unused utility (#269)

Signed-off-by: disksing <i@disksing.com>

config/config.go

@@ -36,10 +36,8 @@ package config
 
 import (
 	"fmt"
-	"net/http"
 	"net/url"
 	"strings"
-	"sync"
 	"sync/atomic"
 
 	"github.com/pingcap/errors"
@@ -205,38 +203,3 @@ func ParsePath(path string) (etcdAddrs []string, disableGC bool, err error) {
 	etcdAddrs = strings.Split(u.Host, ",")
 	return
 }
-
-var (
-	internalClientInit sync.Once
-	internalHTTPClient *http.Client
-	internalHTTPSchema string
-)
-
-// InternalHTTPClient is used by TiDB-Server to request other components.
-func InternalHTTPClient() *http.Client {
-	internalClientInit.Do(initInternalClient)
-	return internalHTTPClient
-}
-
-// InternalHTTPSchema specifies use http or https to request other components.
-func InternalHTTPSchema() string {
-	internalClientInit.Do(initInternalClient)
-	return internalHTTPSchema
-}
-
-func initInternalClient() {
-	clusterSecurity := GetGlobalConfig().Security
-	tlsCfg, err := clusterSecurity.ToTLSConfig()
-	if err != nil {
-		logutil.BgLogger().Fatal("could not load cluster ssl", zap.Error(err))
-	}
-	if tlsCfg == nil {
-		internalHTTPSchema = "http"
-		internalHTTPClient = http.DefaultClient
-		return
-	}
-	internalHTTPSchema = "https"
-	internalHTTPClient = &http.Client{
-		Transport: &http.Transport{TLSClientConfig: tlsCfg},
-	}
-}