Fixed #6657 -- Don't set secure attribute on cookie if `secure=False` is passed, thanks Gulopine.

    def get(self, header, alternate):

        return self._headers.get(header.lower(), (None, alternate))[1]

    def set_cookie(self, key, value='', max_age=None, expires=None, path='/', domain=None, secure=None):

    def set_cookie(self, key, value='', max_age=None, expires=None, path='/', domain=None, secure=False):

        self.cookies[key] = value

        for var in ('max_age', 'path', 'domain', 'secure', 'expires'):

            val = locals()[var]

            if val is not None:

                self.cookies[key][var.replace('_', '-')] = val

        if max_age is not None:

            self.cookies[key]['max-age'] = max_age

        if expires is not None:

            self.cookies[key]['expires'] = expires

        if path is not None:

            self.cookies[key]['path'] = path

        if domain is not None:

            self.cookies[key]['domain'] = domain

        if secure:

            self.cookies[key]['secure'] = True

    def delete_cookie(self, key, path='/', domain=None):

        self.set_cookie(key, max_age=0, path=path, domain=domain,