MPI evaluator tutorial crashes on pass_root_logger_level

[EwoutH]

For some reason the tutorial currently crashes:

The error implicates the problem is with passing the pass_root_logger_level argument in ema_logging.log_to_stderr, which happens here in the tutorial:

if __name__ == "__main__":
    ema_logging.log_to_stderr(level=ema_logging.INFO, pass_root_logger_level=True)

Removing pass_root_logger_level=True resolves the issue. But this is weird and probably unintended behavior, because pass_root_logger_level=True was added to make sure all loggers where logging on the same level. See #299.