This one-click update method was removed in Hotspots 4.0.0, because it's not required anymore. It's powered by Akeeba Live Update, developed by Nicholas K. Dionysopoulos, the lead developer of Akeeba Backup.
Older versions of Hotspots uses a different update method, if
your server supports it. It's called the 'Live Update' feature.
Whenever you visit the Hotspots Control Panel, it will automatically
check for the existence of an updated version and it will notify you.
Clicking on the notification allows you to perform a live update
without further interaction. Do note that if your server is protected
by a firewall, you'll have to enable port 80 and 443 TCP traffic to
cdn.compojoom.com for this
feature to work properly.