Clean up for non-existence issue_id in AO_60DB71_ISSUERANKING table

When you run the following SQL it will return some issue IDs that are ranked by GH but that do not exist in Jira.

select count(*) from "AO_60DB71_ISSUERANKING" 
LEFT JOIN jiraissue ON "ISSUE_ID"=jiraissue.id
where 
("ISSUE_ID" >0) AND jiraissue.id IS NULL

This potentially create some confusion among customers as it looks like there is some inconsistency in the ranking table. Ideally, JA should have a cleaning service to periodically cleanup those non-existing issue id rows.

Note that there is NO functionality broken, this is just how the current issueranking table works.