Missing "small" folder in 3.2.6 release

[expiredemulsion]

Detailed description of the problem

The 3.2.6 release download
https://github.com/LycheeOrg/Lychee/releases/download/v3.2.6/Lychee-v3.2.6.zip
is missing a folder in the uploads dir compared to the source code.
https://github.com/LycheeOrg/Lychee/archive/v3.2.6.zip

The release contains:
big
import
medium
thumb

while the source code contains:
big
import
medium
small
thumb

Steps to reproduce the issue

1. Download release: https://github.com/LycheeOrg/Lychee/archive/v3.2.6.zip
   Download source code: https://github.com/LycheeOrg/Lychee/archive/v3.2.6.zip

2. Compare the "uploads" folders and you will find that the the folder "small" is missing in the release package.

Output of the diagnostics (Settings => Diagnostics)

Error: 'uploads/small' is missing or has insufficient read/write privileges

Browser and system

Lychee Version (json): 3.2.6
DB Version: update_030206
System: Darwin
PHP Version: 7.1
MySQL Version: 50720
Imagick: -
Imagick Active: 0
Imagick Version: -
GD Version: bundled (2.1.0 compatible)
Plugins:

[ildyria]

This will not be solved in the current version, but it will be solved in the next iteration.