We pushed Galleria 1.2.3 to cdnjs yesterday, wich means that you can use their Amazon-powered cloud CDN to host the galleria core files.
F.ex, the 1.2.3 minified source can now be accessed here:
Hopefully this project will be maintained and that the authors will find a way to monetize the service eventually, since running a CDN is a big responsibility. There is a discussion at their support forums that brings up the subject, but the authors are still convinced that a few pledged dollars will be sufficient since hosting scripts is very lightweight.
You can use the CDN right now by replacing thelocal galleria-1.2.3.min.js script tag with: