Fixing issue #2755: updating config storage inside HTTPServer

This patch was authored by @rkreutz and released by @gwynne.

We can update application.storage from within HTTPServer, this way we can keep any changes that happen to the configuration internally up-to-date with the application storage.

This possibly has the least changes and less surface of potential flaws, since we are only adding an extra param and working on top of it. However, now we are setting the application storage from within HTTPServer, there is no issue with that, is just that now we have 2 places changing the storage for the config.

Resolves #2755