Missing dtoken = dtoken in drop_list_folder_continue in drop_dir

I believe you are missing a dtoken = dtoken row 34 of drop_dir function.

```
if (is.null(limit)) {
while (content$has_more) {
content <- drop_list_folder_continue(content$cursor)
results <- append(results, content$entries)
}
}
```

This is causing issue as asking new authentication when going in there.

I am actually not sure why is this code needed why is not everything returned in drop_list_folder ?