fixed key pair vars

ohpc-instance/main.tf

 variable "ohpc_instance_name" {default = "string"}
 variable "image_ohpc" {default = "string"}
 variable "flavor" {default = "string"}
-variable "keypair_name" {default = "string"}
+variable "key_pair" {default = "string"}
 variable "internal_net" {default = "string"}
 variable "external_net" {default = "string"}
 variable "floating_ip_ohpc" {type = string}
@@ -16,7 +16,7 @@ resource "openstack_compute_instance_v2" "ohpc" {
   name            = var.ohpc_instance_name
   image_name      = var.image_ohpc
   flavor_name     = var.flavor
-  key_pair        = openstack_compute_keypair_v2.keypair.name
+  key_pair        = var.key_pair
   security_groups = ["default"]
 
 # defines the networks of the instance