CORS Failure fixed

[Sim4n6]

Hey @honoki ,

I fixed the issue https://github.com/honoki/bbrf-dashboard/issues/4 related to CORS failure. Firefox does issue an OPTIONS methods payloaded with Access-Control-Request-Headers and Access-Control-Request-Method GET that need to be set on the server side to acknowledge the pre flight blocking options request.

The fix is dead simple please check the two lines file changes

regards @Sim4n6