[#68276766] Correct IP for Staging traffic replay
[#68276766] Correct IP for Staging traffic replay

The firewall rule is correct. I used the value of `:a` instead of `:lb_a`.

- https://github.gds/gds/govuk-provisioning/blob/630b4396b1157cad67e2de4debd253d845d4115c/networking/staging_skyscape/firewall.rb#L50
- https://github.gds/gds/govuk-provisioning/blob/630b4396b1157cad67e2de4debd253d845d4115c/networking/staging_skyscape/external_ips.rb#L2

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