Cannot upload pictures with «» in filename

**Describe the bug**

When I try to upload an image with the filename `Kowalski_«Noted».jpg` I get the error message

> Problem uploading image: No Content-Disposition 'form-data' header. Please try again.

When I remove the `«»` it works.

**To Reproduce**
Steps to reproduce the behavior:

1. Create new post
2. Upload image with the filename `Kowalski_«Noted».jpg`

**Expected behavior**

Image gets uploaded.

**Screenshots**


**Smartphone (please complete the following information):**

- Device: Fairphone 3
- OS: Android 13
- Version: 2.35.1