message: work for - Make survey data values reactive - remove undefined values from survey.data
diff: @@ -1267,7 +1267,10 @@ export class SurveyModel extends Base
  public get data(): any {
  var result: { [index: string]: any } = {};
  for (var key in this.valuesHash) {
  - result[key] = this.getDataValueCore(this.valuesHash, key);
  + var dataVelue = this.getDataValueCore(this.valuesHash, key);
  + if(dataVelue !== undefined) {
  + result[key] = dataVelue;
  + }
  }
  return result;
  }
  