project cannot be null, few lines bewore and next line would throw NPE.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@526485 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -799,9 +799,8 @@ public class Main implements AntMain {
             BuildListener listener =
                     (BuildListener) ClasspathUtils.newInstance(className,
                             Main.class.getClassLoader(), BuildListener.class);
-            if (project != null) {
-                project.setProjectReference(listener);
-            }
+            project.setProjectReference(listener);
+
             project.addBuildListener(listener);
         }
     }