message: [bubbles] issue when using duplicated metrics
diff: @@ -954,11 +954,11 @@ class BubbleViz(NVD3Viz):
  self.series = form_data.get('series') or self.entity
  d['row_limit'] = form_data.get('limit')
  - d['metrics'] = [
  + d['metrics'] = list(set([
  self.z_metric,
  self.x_metric,
  self.y_metric,
  - ]
  + ]))
  if not all(d['metrics'] + [self.entity]):
  raise Exception(_('Pick a metric for x, y and size'))
  return d
  