fixed a compilation failure

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@34862 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/tasks/Fingerprinter.java

@@ -289,6 +289,9 @@ public class Fingerprinter extends Recorder implements Serializable {
             }
         }
 
+        public void onAttached(Run r) {
+        }
+
         public void onBuildComplete() {
         }