add validation logs for configured Logger/Audit HTTP targets (#10274)

extra logs in-case of misconfiguration of audit/logger targets

cmd/data-update-tracker_test.go

@@ -42,6 +42,10 @@ type testingLogger struct {
 	t  testLoggerI
 }
 
+func (t *testingLogger) Validate() error {
+	return nil
+}
+
 func (t *testingLogger) Send(entry interface{}, errKind string) error {
 	t.mu.Lock()
 	defer t.mu.Unlock()