screensaver parental rating filter

[d03j]

screensaver doesn't filter movies with empty parental rating. I think this is a bug: as the idea is to show age appropriate imagery on the screensaver, when in doubt, the image should be excluded. so, if a movie doesn't have a rating and the filter is lower than R18+ it should be excluded.

does this make sense? if so, I can log an issue on github.