Fix error found by Dave (and made by me)

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@478939 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/Project.java

@@ -2187,7 +2187,7 @@ public class Project implements ResourceFactory {
      */
     protected void fireMessageLogged(Project project, String message,
                                      int priority) {
-        fireMessageLogged(project, message, priority);
+        fireMessageLogged(project, message, null, priority);
     }
 
     /**