message: [migration] Fixing issue with downgrade
  * [migration] Fixing issue with downgrade
  This PR fixes an issue with the downgrade step of migration which wrongfully labeled the field `metrics` rather than `metric`.
  to:
  * Update fb13d49b72f9_better_filters.py
diff: @@ -94,7 +94,7 @@ def downgrade():
  flts = params.get('filter_configs')
  if not flts:
  continue
  - params['metrics'] = [flts[0].get('metric')]
  + params['metric'] = flts[0].get('metric')
  params['groupby'] = [o.get('column') for o in flts]
  slc.params = json.dumps(params, sort_keys=True)
  except Exception as e:
  