message: Change nightly PIP version to 0.4.4
diff: @@ -50,7 +50,7 @@ from setuptools.dist import Distribution
  # This version string is semver compatible, but incompatible with pip.
  # For pip, we will remove all '-' characters from this string, and use the
  # result for pip.
  -_VERSION = '0.4.3'
  +_VERSION = '0.4.4'
  SETUP_PACKAGES = [
  'pybind11 >= 2.6.0',
  