Version history for issues created prior to using Github Backup

When using Github Backup App on an existing project with existing issues, version history of these existing issues are not displayed in the meta table on Github. Version history is only displayed in the meta table for issues that have been added once Github Backup is in use.

It would be useful to a user of Github Backup App to see version history for issues created prior to using the app. This could be done during the installation process.