TYPO3 Core

Change https://review.typo3.org/53399 introduced a regression.

Thumbnail is regenerated every time process is called with
empty configuration like:

$fileObject->process(ProcessedFile::CONTEXT_IMAGEPREVIEW, []);

Steps to reproduce:
0. truncate processed files table
1. create empty folder
2. upload an image
3. upload same image again and wait for the modal to appear
4. cancel
5. goto 3 (edited)

processed file table is filled with same entries for every time the modal is shown