Fix duplicate variable...

rds/variables.tf

@@ -154,11 +154,6 @@ variable "auto_minor_version_upgrade" {
   default     = true
 }
 
-variable "maintenance_window" {
-  description = "The window to perform maintenance in. Syntax: 'ddd:hh24:mi-ddd:hh24:mi'. See RDS Maintenance Window docs for more information."
-  default     = "Mon:00:00-Mon:01:00"
-}
-
 variable "enabled_cloudwatch_logs_exports" {
   description = "List of log types to enable for exporting to CloudWatch logs. You can check the available log types per engine in the [AWS RDS documentation](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_LogAccess.html#USER_LogAccess.Procedural.UploadtoCloudWatch)."
   type        = list(string)