[fix] google-news engine - KeyError: 'hl in request

Since we added

- 1c67b6ae [enh] google engine: supports "default language"

there is a KeyError: 'hl in request,error pattern::

    ERROR:searx.searx.search.processor.online:engine google news : exception : 'hl'
    Traceback (most recent call last):
      File "searx/search/processors/online.py", line 144, in search
        search_results = self._search_basic(query, params)
      File "searx/search/processors/online.py", line 118, in _search_basic
        self.engine.request(query, params)
      File "searx/engines/google_news.py", line 97, in request
        if lang_info['hl'] == 'en':
      KeyError: 'hl'

Closes: https://github.com/searxng/searxng/issues/154


Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>