Remove bogus indexes created by CONF-21909

When CONF-21909 was prematurely merged to master, deployments containing that merge started down the road to OD deployment. The process was halted short of a full OD rollout, but got at least as far as DOG. The merge has since been reverted on master.

This merge introduced new indexes to 5 different Confluence tables. These new indexes will now need to be manually unpicked from each database to which the deployment was applied.