Investigate cause of service worker cache applying in developer mode.

[jonasKjellerup]

The disable_worker flag that is set when running in development mode, should disable service workers entirely. Despite this the cache somehow manages to trigger anyways.

Edit: I've noticed that using ^R to force reload the page will cause it to temporarily not use cache. It will however revert to old cache on next normal reload (meaning that it does not cache anything from the force reload - which is odd).