TypeError when passing fields to IndexedObject.loadObjects

When passing the `fields` parameter is present in `IndexedObject.loadObjects` we use `hmget` instead of `hgetall`.

`hmget` returns `list` instead of `dict` which causes a `TypeError` at line 176 when trying to do: `r['id'] = ids[idx]`.

This patch converts the result `r` to `dict` using the passed fields before continuing.