API load with shuffle starts at first song anyway

[AndreKR]

Describe the bug
With #330 a shuffle parameter was added to the API call POST /player/load. According to the issue, the purpose of this parameter is to solve this problem:

It is a bit annoying over time, when my playlists always start with the 1st song in the list.

I'm using this shuffle parameter and it does in fact enable shuffle mode, but it still starts with the first song in the playlist.

To Reproduce

• Set up librespot-java with API.
• Assuming librespot-java listens on 192.168.1.1, call:

POST http://192.168.1.1:24879/player/load
Content-Type: application/x-www-form-urlencoded

uri=spotify:playlist:6w7Lsb0JCGEq8f2pBgoZtr&play=true&shuffle=true

It will always start playing with "Jedi Mind Tricks, Sean Price - Blood Runs Cold", the first song in the playlist.

Expected behavior
Playback should start at a random song in the playlist.

Version/Commit
1.6.2 built from https://github.com/librespot-org/librespot-java/archive/refs/tags/v1.6.2.zip using this Dockerfile.