Ensure govuk_base::ruby_app_server specifies apache2
Ensure govuk_base::ruby_app_server specifies apache2

The empty ruby_app_server is used by the 'management' class. At some
point it had been refactored into frontend/backend server and lost the
apache2 class.

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