crash when launching vim as external editor

[drichardson]

Demo of bug here: https://youtu.be/gAuqh-HcpOs

Steps to Reproduce

1. Set EDITOR path to vim, where vim is version 8.1
2. Install Houdini Game Dev Tools
3. In Attribute Wrangle, launch external editor.
4. Enter INSERT mode.

Result

Vim disappears with the following message:

Fatal Python error: initfsencoding: unable to load the file system codec
File "C:/PROGRA~1/SIDEEF~1/HOUDIN~1.229/python27\lib\encodings\__init__.py", line 123
  raise CodecRegistryError

SyntaxError: invalid syntax

Current thread 0x000055f0 (most recent call first):