message: appveyor: VS2019, python3.9, antlr4.9
diff: @@ -18,7 +18,7 @@ environment:
  # add to path otherwise Cython is not found
  PATH: $(PYTHON)\Scripts;$(PATH)
  PLATFORM: x64
  - ANTLR_VER: 4.7
  + ANTLR_VER: 4.9
  #- GENERATOR: -G"Visual Studio 15 2017 Win64"
  # APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
  # BUILD_TYPE: Release
  