Update prepare_reformat to pass preview data. Fixes #782

[E0911CD45B19686]

File "/usr/src/app/helpers/main_helper.py", line 322, in reformat
    if not prepared_format.preview:
AttributeError: 'prepare_reformat' object has no attribute 'preview'

I traced this back to the prepare_format function not passing through the preview attribute to the reformat function. I just added it the same way 'directory' and 'date_format' are used and this fixed the problem for me.

Closes #782

[UltimaHoarder]

Huh, but it's there already

[E0911CD45B19686]

That's not checked in or pushed to the master branch https://github.com/DIGITALCRIMINAL/OnlyFans/blob/master/classes/prepare_metadata.py#L370

[UltimaHoarder]

Nvm... It was for a different project, but I forgot to replicate it on this. Thanks 👍