terraform: Fix broken target group labels

terraform/loadbalancer.tf

@@ -7,7 +7,7 @@ resource "hcloud_load_balancer" "lb" {
 resource "hcloud_load_balancer_target" "lb_target" {
   type             = "label_selector"
   load_balancer_id = hcloud_load_balancer.lb.id
-  label_selector   = "k8s.io/node=true"
+  label_selector   = "k8s.io/node"
   use_private_ip   = false
 }