Logic is definitely not correct but putting it back to static

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@270945 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/optional/junit/JUnitTestRunner.java

@@ -129,7 +129,7 @@ public class JUnitTestRunner implements TestListener {
     /**
      * Do we filter junit.*.* stack frames out of failure and error exceptions.
      */
-    private boolean filtertrace = true;
+    private static boolean filtertrace = true;
     
     private final static String[] DEFAULT_TRACE_FILTERS = new String[] {
                 "junit.framework.TestCase",