🐛[Bug] Initial backups not created when using relative paths

[tofof]

Steps to reproduce:

1. Create "autover_backups" folder one level up from watched folder.
2. Set Backup to: to ..\autover_backups (note: double period)
3. Checkmark Create initial backup, OK out of dialog.
4. Observe bug: No initial backup creation occurs ("autover_backups" folder stays empty)
5. Re-enter watcher properties, change Backup to: to full path to "autover_backups" folder.
6. Checkmark Create initial backup, OK out of dialog.
7. Observe expected behavior: Initial backup creation occurs.
8. Delete backups, emptying "autover_backups" folder.
9. Re-enter watcher properties, change Backup to: back to relative path (..\autover_backups)
10. Checkmark Create initial backup, OK out of dialog.
11. Observe bug: once again no initial backup creation occurs.