My understanding is that there have been a lot of recent security issues with Magento, so we used to unpublish older versions, maybe that's why that version got unpublished.
You could try to download the following installer and install it in your instance:
Run it with
sudo and install it to
/opt/bitnami so the installations are as similar as possible.
Keep in mind that the installer includes the exact same version of Magento (18.104.22.168), but with a newer Bitnami revision (number 3), which includes an OpenSSL security issue fix (CVE-2016-6304).
However, please keep in mind there have been security incidents since then, CVE-2017-3731, CVE-2016-7055, CVE-2017-5340 and CVE-2017-1000367 so we recommend you upgrade to the latest version of Magento as soonest as possible.
I hope it helps!