[BUG] Cant bind IP to 7 days to die

As a server owner, I want to bind a specific public IP in the 7 days to die config file to the server.

## Basic info

* **Distro:** [Ubuntu 20.04]
* **Game:** [7 Days to Die]
* **Command:** [Start/Details]
* **LinuxGSM version:** [v21.5.1]

## Further Information

In /lgsm/config-lgsm/sdtdserver/sdtdserver.cfg I set ip="72.9.144.140", however this server IP variable doesn't actually get injected anywhere in the startup parameters.
startparameters="-quit -batchmode -nographics -dedicated -configfile=${servercfgfullpath}"
This leads to the server ALWAYS binding to the main IP address only and can not be binded to a 2nd ip address on the server.

## To Reproduce

Steps to reproduce the behaviour:
1. Set 2nd IP address in sdtdserver.cfg
2. Start Server
3. See server Binds only to 1st Main IP Address

## Expected behaviour

Bind to a 2nd IP address properly