How to stop the automatic backup

Im tired of Calibre taking forever to close and I am not happy that I have a ton of backup .zips in the calibre-backup folder in appdata>roming.

How can I stop this? I would prefer to initate the saving of backups rather than having it do it every time I close out. I recall selecting to "back up calibre settings" ONCE. Is it happening every time now?


EDIT
I guess it was a plugin - sorry.