server: better reverse proxy headers handling: reverse proxy header were not used if `X-Forwarded-Host` was not set, with this patch `X-Forwarded-Host` and `X-Forwarded-Proto` are check independently. Furthermore, the new standardised `Forwarded` header is not checked too. fix 396

"""manage common dialogs"""

from browser import document

def remove_loading_screen():
    print("removing loading screen")
    document['loading_screen'].remove()