add assertion

options.nix

@@ -155,10 +155,15 @@ in
      prototype : (expression A ) && tests || !(expression A) ->   réalise le test si A est satisfait, et continue sinon = pas de politique
     */
     assertions = [
+     {
+       assertion = (currentMachine.profiles.isWorkstation && (currentMachine.configurationFlags.graphical == true))
+       || (!currentMachine.profiles.isWorkstation);
+       message = "A workstation requires a graphical environement.";
+     }
      {
        assertion = (currentMachine.profiles.isDesktopEnvironment && (currentMachine.configurationFlags.graphical == true))
        || (!currentMachine.profiles.isDesktopEnvironment);
-       message = "A workstation requires a graphical environement.";
+       message = "A desktop station requires a graphical environement.";
      }
      {
        assertion = (currentMachine.profiles.isDesktopEnvironment && (config.services.xserver.enable == true))