Try to fix ACME directory problem (#33072) (#33077)

Backport #33072 by wxiaoguang

Haven't really confirmed, but I think it might fix #32191

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

cmd/web_acme.go

@@ -54,7 +54,7 @@ func runACME(listenAddr string, m http.Handler) error {
 		altTLSALPNPort = p
 	}
 
-	magic := certmagic.NewDefault()
+	magic := &certmagic.Default
 	magic.Storage = &certmagic.FileStorage{Path: setting.AcmeLiveDirectory}
 	// Try to use private CA root if provided, otherwise defaults to system's trust
 	var certPool *x509.CertPool