logging module: AttributeError: 'FileIO' object has no attribute 'flush' micropython 1.18

The stream handler constructor called at the end of `__init__.py` initializes the _stream as stderr. This is a FileIO object, which does not have a "flush" method. This results in the above error.

Patching the StreamHandler class "flush" method to read like this solves the problem:

```
    def flush(self):
        if hasattr(self._stream, "flush"):
            self._stream.flush()

```
