cloud/lib/component: fix gRPC client cert verification

Change-Id: I5eda3e9e898c25a804ed8570150b6b05777b41e2
Reviewed-on: https://review.monogon.dev/c/monogon/+/1596
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/cloud/lib/component/component.go b/cloud/lib/component/component.go
index dee4703..9337d52 100644
--- a/cloud/lib/component/component.go
+++ b/cloud/lib/component/component.go
@@ -100,7 +100,7 @@
 	tlsConf := &tls.Config{
 		Certificates: []tls.Certificate{pair},
 		ClientAuth:   tls.RequireAndVerifyClientCert,
-		RootCAs:      certPool,
+		ClientCAs:    certPool,
 	}
 	return []grpc.ServerOption{
 		grpc.Creds(credentials.NewTLS(tlsConf)),