chore(http): remove stale default_client.go

internal/net/gphttp/default_client.go

@@ -1,28 +0,0 @@
-package gphttp
-
-import (
-	"crypto/tls"
-	"net"
-	"net/http"
-	"time"
-)
-
-var (
-	httpClient = &http.Client{
-		Timeout: 5 * time.Second,
-		Transport: &http.Transport{
-			DisableKeepAlives: true,
-			ForceAttemptHTTP2: false,
-			DialContext: (&net.Dialer{
-				Timeout:   3 * time.Second,
-				KeepAlive: 60 * time.Second, // this is different from DisableKeepAlives
-			}).DialContext,
-			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
-		},
-	}
-
-	Get  = httpClient.Get
-	Post = httpClient.Post
-	Head = httpClient.Head
-	Do   = httpClient.Do
-)