increase vCPU to 2 and make variable ssh_key optional

multiple/shared_modules/variables.tf

@@ -49,6 +49,7 @@ variable "enable_cloudinit" {
 variable "ssh_key" {
   description = "SSH authorized keys for cloud-init"
   type        = string
+  default = ""
 }
 
 variable "user_data" {
@@ -70,7 +71,7 @@ variable "memory" {
 variable "vcpu" {
   description = "Number of virtual CPUs"
   type        = number
-  default     = 1
+  default     = 2
 }
 
 variable "network_mode" {