Setup.sh does not work

[Niolak]

Describe the bug
The setup script does not work: ruby dependencies are not installed.

To Reproduce
Steps to reproduce the behavior:

1. Follow the installation guide
2. See logs inviting to execute commands to install gems
3. See the FabManager container restarting repeatedly with the error: "Error: Cannot open an HTTP server: socket.error reported errno.EACCES"

Expected behavior
FabManager should just work after installation.

Server:

• OS: Debian 13
• Kernel: Linux vps-2d757122 6.12.48+deb13-cloud-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.48-1 (2025-09-20) x86_64 GNU/Linux
• Fab-manager version: latest (on January 8th)