message: add EITHER to config error message
  Fixes
  This further clarifies mutual exclusivity between zoned and zoneless
  deploy configurations
diff: @@ -7,7 +7,9 @@ impl DeployConfig {
  route_config: &RouteConfig,
  ) -> Result<DeployConfig, failure::Error> {
  if route_config.is_valid() {
  - failure::bail!("you must set workers_dev = true OR provide a zone_id and route/routes.")
  + failure::bail!(
  + "you must set EITHER workers_dev = true OR provide a zone_id and route/routes."
  + )
  }
  if route_config.is_zoneless() {
  