Update documentdb.tf (#6)

* Update documentdb.tf

* Disable ssl by default

* Address comemnts

Author: goruha

documentdb.tf

@@ -46,8 +46,15 @@ variable "documentdb_preferred_backup_window" {
 }
 
 variable "documentdb_cluster_parameters" {
-  type        = "list"
-  default     = []
+  type = "list"
+
+  default = [
+    {
+      name  = "tls"
+      value = "disabled"
+    },
+  ]
+
   description = "List of DB parameters to apply"
 }