Added comment

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@5567 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/userinterface/properties/GUIMultiProperties.java

@@ -1219,6 +1219,7 @@ public class GUIMultiProperties extends GUIPlugin implements MouseListener, List
 			Thread t = new LoadPropertiesThread(this, parsedModel, new File(argsPropertiesFile));
 			t.setPriority(Thread.NORM_PRIORITY);
 			t.start();
+			//we clear the variable to avoid loading property file every time a model is parsed.
 			argsPropertiesFile = null;
 		}
 	}