Check if the command line has no arguments or only the --conf optional argument.

def has_void_args(argv):
    """
    Check if the command line has no arguments or only the --conf optional argument.
    """
    n_args = len(argv)
    return n_args == 1 or n_args == 2 and argv[1].startswith('--conf=') or n_args == 3 and argv[1] == '--conf'