[AI] TypeError: Cannot get property 'getAttribute' of undefined or null

[Crashillo]

View details in Rollbar: https://rollbar.com/Populate/gobierto/items/3033/

TypeError: Cannot read property 'getAttribute' of null
  File "webpack:https:///./node_modules/d3-selection/src/selection/attr.js", line 50, in [anonymous]
            : node.getAttribute(fullname);
  File "webpack:https:///./app/javascript/lib/visualizations/modules/card_sparkline_table.js", line 12, in SparklineTableCard
        this.dataType = this.div.attr('data-type');
  File "webpack:https:///./app/javascript/gobierto_observatory/modules/classes/death_rate.js", line 123, in e.<anonymous>
            new SparklineTableCard(this.container, deathsPlace, this.nest, 'deaths');
  File "webpack:https:///./node_modules/d3-queue/src/queue.js", line 36, in await
        this._call = function(error, results) { callback.apply(null, [error].concat(results)); };
  File "webpack:https:///./node_modules/d3-queue/src/queue.js", line 113, in maybeNotify
        q._call(q._error, d);
  File "webpack:https:///./node_modules/d3-queue/src/queue.js", line 84, in end
          else maybeNotify(q);
  File "webpack:https:///./node_modules/d3-request/src/request.js", line 115, in send
          if (callback != null) request.on("error", callback).on("load", function(xhr) { callback(nul...
  File "webpack:https:///./node_modules/d3-dispatch/src/dispatch.js", line 57, in call
        for (t = this._[type], i = 0, n = t.length; i < n; ++i) t[i].value.apply(that, args);
  File "webpack:https:///./node_modules/d3-request/src/request.js", line 40, in respond
          event.call("load", request, result);