message: Removed double call to ConnectorRegistry.sources
  Removing the double call didn't cause any adverse effects upon removal. If required, a comment motivating the double call should be added.
diff: @@ -2083,7 +2083,6 @@ class Superset(BaseSupersetView):
  SqlaTable = ConnectorRegistry.sources['table']
  data = json.loads(request.form.get('data'))
  table_name = data.get('datasourceName')
  - SqlaTable = ConnectorRegistry.sources['table']
  table = (
  db.session.query(SqlaTable)
  .filter_by(table_name=table_name)
  