remove 'feedback' zip files older than 30 days

[dovholuknf]

When checking for older downloads to remove, add a check for old zip files that should be removed as well. The 'feedback' zip files don't ever clean themselves up. While not a high-volume activity they do add up over time. Alternatively consider removing zip files which are from the same day since those will all contain redundant files for that day. only the 'latest one' is important