Code review comment for lp:~ken-vandine/ubuntu-system-settings/lp1365646

We don't want to tell system-image-dbus to download the system update if auto_download isn't enabled.

I'm not certain why using contentItem to get the height was causing the crash, it seemed to only happen when the system update was already downloaded, so got added to the model while the click updates were getting added. Note the system update gets prepended to the model, so maybe it has something to do with the reordering of the rows.