In 1.3, we now attribute Goals correctly to Campaigns. As a result, it is possible that a user arrives via a Campaign on the site, and converts a Goal, but actually the Goal was attributed to a previous campaign (used by the visitor 1 hour ago, or 10 days ago).
There is now a discrepency between:
The problem is that, for Referrers, we cannot compute and display the Global Conversion Rate. So we should only display, individual conversion rates.
(In ) Fixes #2346
API Breaking: nb_visits_converted not already in response anymore (only when there is no "per goal" metrics for this report)