Fix Performance Platform Smokey parameter
Fix Performance Platform Smokey parameter

This has never been correct since it was added in
20b7c6594b99ad2058ee3b92c2caf3ea4f056584.

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet