"Motion Photos" create entries for missing files in autoupload list

### Actual behaviour
The Harry Potter-esque Motion Photos (Android naming - iOS calls it Live Photos) are uploaded as they should, but it seems as if there are temporary jpeg files which are tried to be autouploaded but then could not be found. This creates a lot of entries in the "uploads" sections of the app with the following content:
"IMG_20181028_161552_095.jpg - Lokale Datei nicht gefunden"
The file name of the correctly uploaded motion picture is silghtly different: MVIMG_2018... There is no file in the local photo directory without the MV in front of the filename.

### Expected behaviour
Just ignore the temporary created jpg files.

### Steps to reproduce
Settings:
- Only on WIFI: yes
- Only when charging: no
- Use subfolders: yes
- Keep original files: in original folder

### Environment data
Android version:
8.1 (Android One)

Device model:
BQ Aquaris X2

Stock or customized system:
Stock

Nextcloud app version:
3.3.2

Nextcloud server version:
14.0.3