kubeadm init phase upload-certs: add flag --kubeconfig

Author: zhanw15

cmd/kubeadm/app/cmd/phases/init/uploadcerts.go

@@ -37,6 +37,7 @@ func NewUploadCertsPhase() workflow.Phase {
 		Run:   runUploadCerts,
 		InheritFlags: []string{
 			options.CfgPath,
+			options.KubeconfigPath,
 			options.UploadCerts,
 			options.CertificateKey,
 			options.SkipCertificateKeyPrint,