Can't use SVG files for post picture #352

Describe the bug
on staging and alpha: svg file on post not shown
https://staging.human-connection.org/contributions/edit/die-haufigsten-comunity-fragen

To Reproduce
Steps to reproduce the behavior:

1. Go to make new post (+)
2. Click on that symbol
3. Scroll down to upload picture
4. See error

Expected behavior
using SVG Graphics files should be possible and create the same results like with PNG files

Desktop (please complete the following information):

• OS: Ubuntu 18.04 LTS
• Browser Firefox & Chromium
• Version the very latest

Additional context
i found this myself while setting up the following post (used PNG finally for alpha)
https://alpha.human-connection.org/contributions/die-haufigsten-comunity-fragen

Screenshots

human-connection-logo.zip