Updates an address to the Abook addressbook
        uid -- uid of the entry to replace
        vcard -- vCard of the new content
        filename -- unused

def replace_vobject(self, uid, vcard, filename=None):
        """Updates an address to the Abook addressbook
        uid -- uid of the entry to replace
        vcard -- vCard of the new content
        filename -- unused
        """
        entry = uid.split('@')[0]

        book = ConfigParser(default_section='format')
        with self._lock:
            book.read(self._filename)
            Abook.to_abook(vcard, entry, book, self._filename)
            with open(self._filename, 'w') as fp:
                book.write(fp, False)

        return Abook._gen_uid(self._book[entry])