Get configuration value from PYMP/OMP env variables.

def _get_conf_value(suffix):
    """Get configuration value from PYMP/OMP env variables."""
    pymp_name = "PYMP_" + suffix
    omp_name = "OMP_" + suffix
    value = None
    for env_name in [pymp_name, omp_name]:
        # pylint: disable=no-member
        if env_name in _os.environ:
            _LOGGER.debug(
                "Using %s environment variable: %s.", env_name, _os.environ[env_name]
            )
            value = _os.environ[env_name]
            break
    return value