worng example on sync_plan doc

[vhsantos]

On the sync_plan doc

# Autogenerated example with required keys
resource "foreman_katello_sync_plan" "example" {
  cron_expression = "*/5 * * * *"
  description = "A sync plan description"
  enabled = true
  interval = "daily"
  name = "daily"
  sync_date = "1970-01-01 00:00:00 UTC"
}

there is a small error, because you cant have the interval = "daily" and cron_expression at the same time.. it generate a error after the first apply. :-)