adding one more constructor.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@7622 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/util/StreamTaskListener.java

@@ -47,6 +47,13 @@ public final class StreamTaskListener implements TaskListener, Serializable {
         this(new WriterOutputStream(w));
     }
 
+    /**
+     * Creates {@link StreamTaskListener} that swallows the result.
+     */
+    public StreamTaskListener() {
+        this(new NullStream());
+    }
+
     public PrintStream getLogger() {
         return out;
     }