Minor fix to "LWN.net Weekly Edition"

[Higgs.Mechanism]

Looks like the site made a small change to the login form, Updating het_browser seems to fix this both with and without a username being specified.

    def get_browser(self):
        br = BasicNewsRecipe.get_browser(self)
        if self.username is not None and self.password is not None:
            br.open('https://lwn.net/Login/')
            br.select_form(name='loginform')
            br['uname'] = self.username
            br['pword'] = self.password
            br.submit()
        return br

[kovidgoyal]

Yeah the builtin one was updated a short while back.