Issue Summary

When changing a workspace avatar, it generates a HTTP 400 error.
This issue is reproducible only in workspace avatar on Firefox browser. Tested on Firefox 91.0.2 (64-bit)
Works well on Google Chrome

Steps to Reproduce

1. Open your Firefox browser
2. Navigate to your Workspace Settings
3. Click "Change avatar" on the right hand side of the page
4. Upload a JPEG or PNG Image

Expected Results

Image gets uploaded to workspace as avatar successfully

Actual Results

• Bitbucket responds that image is uploaded
• However image is not uploaded
• Open browser console and you'll see this error message :

  • Only image/{png,jpeg,gif} content-types are allowed.
    

Workaround

• Workaround is to use Google Chrome browser to upload the workspace avatar.