Fix for Deuce's previous commit: USER_ICE_COLOR was assumed to be defined

This broke showmsgavatar.js

exec/load/graphic.js

-// $Id: graphic.js,v 1.84 2020/07/27 02:37:17 rswindell Exp $
-
 /*
  * "Graphic" object
  * Allows a graphic to be stored in memory and portions of it redrawn on command
  */
 
+require("userdefs.js", "USER_ICE_COLOR");
+
 /*
  * Class that represents a drawable object.
  * w = width (default of 80)