Server example: [failed to negotiate security protocol] general error

Testing the server example from the latest release ironrdp-v0.7.3 against Remmina Remote Desktop Client (libfreerdp 3.10.3), I keep running into these errors while trying to connect:

```
Running `target/debug/examples/server`
2025-01-28T14:45:15.333805Z ERROR ironrdp_server::server: Connection error error=accept_begin failed

Caused by:
[failed to negotiate security protocol] general error
2025-01-28T14:45:15.338022Z ERROR ironrdp_server::server: Connection error error=accept_begin failed

Caused by:
[failed to negotiate security protocol] general error
```

In Remmina, I set the host to 127.0.0.1 and leave the username/password at their default settings. In addition to these messages, the client fails to connect.

Start by running the server example from ironrdp-v0.7.3 and connecting from Remmina with host 127.0.0.1 and its default username/password settings. Compare the failed security-protocol negotiation and connection errors with a successful connection; done means the server example accepts the Remmina connection without these errors.

Written by the indexing model from the issue text.