Created Issue: [pykd_bootstrapper_2.0] second load of pykd leads to hung up [14137]

```
0:000> .load pykd
0:000> !py
Python 2.7.13 (v2.7.13:a06454b1afa1, Dec 17 2016, 20:53:40) [MSC v.1500 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> quit()
0:000> .load pykd
0:000> !py
```
Last command leads to hang up