make it possible to open additional ports on master nodes (#6547)

contrib/terraform/openstack/modules/compute/variables.tf

@@ -114,6 +114,10 @@ variable "supplementary_node_groups" {
   default = ""
 }
 
+variable "master_allowed_ports" {
+  type = list
+}
+
 variable "worker_allowed_ports" {
   type = list
 }