Small images get pixelated when added to posts

[LinHuiqing]

Describe the bug

Small images get pixelated when added to posts because they are resized.

To Reproduce
Steps to reproduce the behavior:

1. Login
2. Click 'Add post'
3. Upload a small image in the answer

Expected behavior

Small image should remain small.

Screenshots

Image uploaded:

How image shows up in post:

Desktop (please complete the following information):

• OS: iOS
• Chrome
• Version 96.0.4664.55 (Official Build) (x86_64)

Additional context

Bug found in PR #875