Issue Summary

Configure a cleanup task to verify and drop it from plugin_setting table

Steps to Reproduce

1. Configure Application link between Bitbucket and Jira Cloud
2. Users have authorised the application from both Bitbucket and Jira and integration is working fine.
3. A user's email ID is updated in external directory and synchronised to Bitbucket. Everything remains same in Bitbucket as just email attribute updated and username is unaltered. While in Jira cloud Login is based on email ID, the old user becomes inactive and new email ID will be considered as new account to Jira cloud.
4. When user tries to access Jira issues in Bitbucket, they encounter 'connection lost to Jira' error since Jira cloud don't recognise the OAuth token generated with old email ID.