Unfortunately, there is no way to change it. The old installer (that works with this site) will not work on the newer firmwares.

As Installer is quite literally a dying app, you should really consider switching over to Cydia instead, which offers way more packages, and way better performance -- and also no need for meta data repository such as this one.

You can find Cydia on Saurik's source. For more information, please read here:
Bringing Debian APT to the iPhone - Jay Freeman (saurik)