accept absence of roomAcoustics in text_to_binary_payload.py input

            sections[section_name] = config[section_name]

    # parse room acoustics

    if 'roomAcoustics' in sections:

    hasAcEnv = len(sections['roomAcoustics']) > 0

    data = bitarray(get_bool_code(hasAcEnv))                                            # hasAcEnv (see IVAS acoustic environment payload syntax document)

    if hasAcEnv:

        frequencyGridCount = eval_option(sections['roomAcoustics']['frequencyGridCount'])

        acousticEnvironmentCount = eval_option(sections['roomAcoustics']['acousticEnvironmentCount'])

        assert frequencyGridCount == len(sections['frequencyGrid'])

        assert acousticEnvironmentCount == len(sections['acousticEnvironment'])

        # parse frequency grids

    data = bitarray(

          '1'                                                                       # hasAcEnv (see IVAS acoustic environment payload syntax document)

        + get_count_or_index_code(len(sections['frequencyGrid'])),                  # fgdNrGrids

        data += bitarray(

            get_count_or_index_code(len(sections['frequencyGrid'])),                    # fgdNrGrids

            endian='big')

        for _, fg in sections['frequencyGrid'].items():

            method = eval_option(fg['method'])

    # parse directivity

    hasDirectivity = len(sections['directivity']) > 0

    data += get_bool_code(hasDirectivity)                                                                      # hasDirectivity

    data += bitarray(get_bool_code(hasDirectivity))                                     # hasDirectivity

    if hasDirectivity:

        dir_values = eval_option(sections['directivity']['directivity'])

        data += bitarray(get_angle_code(dir_values[0])                                  # Directivity inner angle