feat(fofserver): update default number of players (#2548)

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

@@ -14,7 +14,7 @@ port="27015"
 clientport="27005"
 sourcetvport="27020"
 defaultmap="fof_depot"
-maxplayers="16"
+maxplayers="20"
 
 ## Server Start Command | https://docs.linuxgsm.com/configuration/start-parameters#additional-parameters
 fn_parms(){