Make enabling cloud_init optionnal

For cloud images that needs it, cloud_init can be enabled in the main.tf file. This change will allow deployments that does not require cloud_init to be supported

multiple/shared_modules/variables.tf

@@ -40,6 +40,12 @@ variable "cloudinit_filename" {
   default     = "commoninit.iso"
 }
 
+variable "enable_cloudinit" {
+  description = "Enable cloud-init support"
+  type        = bool
+  default     = false
+}
+
 variable "ssh_key" {
   description = "SSH authorized keys for cloud-init"
   type        = string