[patches] firstboot - fix auth parameters

With ff65318ba52109f4ca7eb83a639ecddda2a8b3fc luci changed name of auth
parameters to "attempt to work around Firefox autocomplete bugs".
They were changed from username and password to luci_username and
luci_password.

Fixes #136.
Merge pull request #137 from freifunk-berlin/bugs/firstboot_redirect_fix

[patches] firstboot - fix auth parameters