Fix broken Cloud doc link

Author: Nik Richers

docs/upgrading-stack.asciidoc

@@ -141,4 +141,4 @@ To avoid downtime on production clusters due to major version upgrades:
 . Delete the old cluster to stop incurring additional costs. You are billed extra only for the time that the additional cluster was running. Billing for usage is by the hour.
 
 To learn more about the upgrade process on Elastic Cloud, see {cloudref}/ec-upgrading.html[
-Upgrade Versions] and {cloudref}/ec-deployment-config.html[Configuring Elastic Cloud].
+Upgrade Versions] and {cloudref}/ec-configure.html[Configuring Elastic Cloud].