[locale] Update language even if there is a current location

- the first time we arrive at locale, there isn't a current location
  and the setCurrentLocation(...) method ends up calling setLanguage(),
  usually. The second time, this call is skipped (not called from
  the overloaded setCurrentLocation() which is called from onActivate),
  so the language didn't update.
- now call setLanguage() unless there has been one set explicitly.

src/modules/locale/Config.cpp

@@ -221,6 +221,11 @@ Config::setCurrentLocation()
     {
         setCurrentLocation( m_startingTimezone.first, m_startingTimezone.second );
     }
+    if ( !m_selectedLocaleConfiguration.explicit_lang )
+    {
+        auto newLocale = automaticLocaleConfiguration();
+        setLanguage( newLocale.language() );
+    }
 }
 
 void