fix(cs2): add gslt variable

lgsm/config-default/config-lgsm/cs2server/_default.cfg

@@ -15,6 +15,11 @@ port="27015"
 maxplayers="16"
 wsapikey=""
 
+## Game Server Login Token (GSLT): Required
+# GSLT is required for running a public server.
+# More info: https://docs.linuxgsm.com/steamcmd/gslt
+gslt=""
+
 ## Server Parameters | https://docs.linuxgsm.com/configuration/start-parameters#additional-parameters
 startparameters="-dedicated -ip ${ip} -port ${port} -maxplayers ${maxplayers} -authkey ${wsapikey} +exec ${selfname}.cfg"