PDF to text is being executed on non-pdf files

[txau]

Describe the bug We are seeing a few messages about attempts to extract text from non-PDF files:

pdftotext /tmp/1663821835115nhezigjjt9m.jpeg - failed with code 1
stderr output:
Syntax Warning: May not be a PDF file (continuing anyway)

To Reproduce It is unclear how to reproduce. Likely via CSV import with attached files?

Expected behavior Non-PDF files should not be allowed as main file for the moment.