slow_mo photos always have hasadjustments=True even if not edited

[RhetTbull]

Need to find a way to determine if slow_mo video really has adjustments.

I think I've found the problem and I've been able to replicate this. It appears that slow-mo videos are always marked as having adjustments (edits) in the database even if they haven't been edited. Instead of an edited video there's a .plist file and my guess is this contains the information for when to change frame rate between normal speed and slow motion. Thus, when using --skip-original-if-edited, osxphotos looks for an edited file but doesn't find one. If you actually edit the file, e.g. trim it, there will be an edited video generated and the export works as expected.

I'll add a check to osxphotos to look for this situation and export the original video if the file hasn't actually been edited.

Originally posted by @RhetTbull in #252 (comment)