Increase nginx logrotate on backend-lb to 45 days
Increase nginx logrotate on backend-lb to 45 days

It's useful to have more logs on the backend loadbalancers, because they
are the single point of all backend requests.

45 days is a number that's probably useful because that's how long
Signon passwords are valid for.

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