Backups are stored on webserver even if option is deselected

[W3ap0n-X]

Description:
As a user, my web host may only provide a small amount of storage, or may not allow local storage of backups.
If I select remote backups, and uncheck the option for Web Server storage. Regardless of the check box, local backups still obey the retention settings, storing 5 by default and always at least one.

To Reproduce:
Steps to reproduce the behavior:

1. Configure a remote backup location, and uncheck the box for web server storage
2. Make a few backups, enough to exceed the retention settings for the web server's config details
3. Note that total upkeep obeys the web server retention settings

Expected behavior:
If the Web Server option is deselected and a remote location is selected, all local backups should be removed, provided that they have been successfully uploaded to a remote location.