message: Fixing null reference issue
diff: <app-gallery-directories class="directories"
  - [directories]="directoryContent.directories || []"></app-gallery-directories>
  + [directories]="directoryContent?.directories || []"></app-gallery-directories>
  <div class="blog-map-row">
  <div class="blog-wrapper"
  [style.width]="blogOpen ? '100%' : 'calc(100% - 100px)'"
  - *ngIf="config.Client.MetaFile.markdown && directoryContent.metaFile && (directoryContent.metaFile | mdFiles).length>0">
  + *ngIf="config.Client.MetaFile.markdown && directoryContent?.metaFile && (directoryContent.metaFile | mdFiles).length>0">
  <app-gallery-blog [collapsed]="!blogOpen"
  [mdFiles]="directoryContent.metaFile | mdFiles"></app-gallery-blog>
  </button>
  </div>
  <app-gallery-map *ngIf="isPhotoWithLocation && mapEnabled"
  - [photos]="directoryContent.media | photosOnly"
  - [gpxFiles]="directoryContent.metaFile | gpxFiles"></app-gallery-map>
  + [photos]="directoryContent?.media | photosOnly"
  + [gpxFiles]="directoryContent?.metaFile | gpxFiles"></app-gallery-map>
  </div>
  - <app-gallery-grid [media]="directoryContent.media"
  + <app-gallery-grid [media]="directoryContent?.media"
  [lightbox]="lightbox"></app-gallery-grid>
  </ng-container>
  