App.port needs to be added to _default.cfg

Rust repo for your default configurations is missing app.port for mobile support
/home/linuxgsm/lgsm/config-lgsm/rustserver/_default.cfg
You can add it to your parms and at the top for mobileport or appport.
I have been doing this manually.

app.port is the command rust is using
app.port “#port-number

I have added a pull request to make the changes needed for this.