[Bug]: Can't stop Rust server gracefully

[HunterZ]

User story

As a rust server owner, I need LGSM to stop the server via a quit RCON command to trigger a clean save on exit

Game

Rust

Linux distro

Ubuntu 24.04

Command

command: stop

Further information

LGSM's default stopmode for Rust is CTRL+C, which causes a hard shutdown that tends to have nasty side effects like forgetting teams, because the server doesn't get a chance to generate a full save.

Changing stopmode to quit results in failure, apparently because LGSM tries to send it to the server console instead of via RCON.

Relevant log output

rustserver@ubuntultsvm:~$ ./rustserver stop
[ ERROR ] Stopping rustserver: Graceful: sending "quit": FAIL
[  OK  ] Stopping rustserver: LinuxGSM

### Steps to reproduce

1. Configure server for `stopmode=3`
2. `./rustserver start` and wait for server startup to complete
3. `./rustserver stop`