try loading config file from a default directory

def load_config():
    '''try loading config file from a default directory'''
    cfg_path = '/usr/local/etc/freelan'
    cfg_file = 'freelan.cfg'

    if not os.path.isdir(cfg_path):
        print("Can not find default freelan config directory.")
        return

    cfg_file_path = os.path.join(cfg_path,cfg_file)

    if not os.path.isfile( cfg_file_path ):
        print("Can not find default freelan config file.")
        return

    return _load_config(cfg_file_path)