Fix selection

mobile/lib/models/selected_files.dart

@@ -75,6 +75,8 @@ class SelectedFiles extends ChangeNotifier {
       }
     } else if (first.uploadedFileID != null && second.uploadedFileID != null) {
       return first.uploadedFileID == second.uploadedFileID;
+    } else if (first.asset != null && second.asset != null) {
+      return first.asset!.id == second.asset!.id;
     }
     return false;
   }