message: add XMP subject to keywords only if keyword is not yet exisiting
diff: @@ -218,9 +218,11 @@ export class MetadataLoader {
  }
  if(exif.subject && exif.subject.value){
  for(let i=0; i < exif.subject.value.length; i++){
  + if(metadata.keywords.indexOf(exif.subject.value[i].value) == -1) {
  metadata.keywords.push(exif.subject.value[i].value);
  }
  }
  + }
  if (exif.Orientation) {
  metadata.orientation = (parseInt(exif.Orientation.value as any, 10) as any);
  if (OrientationTypes.BOTTOM_LEFT < metadata.orientation) {
  