Handle re-index failure during watcher setup (JEMH-7180)

Failed indexing is unlikely to have been triggered by JEMH. Existing mitigation for re-indexing failure has been available since JEMH 3.0.22. Please see relevent Atlassian documentation for diagnosing and resolvign this issue:

• https://confluence.atlassian.com/jirakb/reindexing-failed-com-atlassian-jira-index-indexingfailureexception-indexing-completed-with-1-errors-776811617.html