Revert "Change refcount logic in ImportHook.Shutdown"
Revert "Change refcount logic in ImportHook.Shutdown"

This reverts commit 82034dcb503bae528eb1c112017015f9d0410532.

AlexCatarino/pythonnet,pythonnet/pythonnet,AlexCatarino/pythonnet,QuantConnect/pythonnet,AlexCatarino/pythonnet,QuantConnect/pythonnet,pythonnet/pythonnet,QuantConnect/pythonnet,pythonnet/pythonnet,AlexCatarino/pythonnet