[fix] update_languages.py: no excption on unknown locale & language

Fix exception handling of unknown locales and languages::

    ERROR: ca_ES_valencia --> [Errno 2] No such file or directory: 'local/py3/lib/python3.8/site-packages/babel/locale-data/ca_ES_valencia.dat'
    ERROR: languages['fil-PH'] --> {'name': None, 'english_name': None}
    ERROR: languages['nb-NO'] --> {'name': None, 'english_name': None}

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