/usr/bin/az extension add --upgrade --name ssh failed under wsl

### **This is autogenerated. Please review and update as needed.**

## Describe the bug

**Command Name**
`az extension add`

**Errors:**
```
...
```

## To Reproduce:
Steps to reproduce the behavior. Note that argument values have been redacted, as they may contain sensitive information.

- _Put any pre-requisite steps here..._
- `az extension add --upgrade --name {}`

## Expected Behavior

## Environment Summary
```
Windows-10-10.0.19041-SP0
Python 3.6.8
Installer:

azure-cli 2.20.0 *

Extensions:
hcs 0.1.0
ssh 0.1.5

```
## Additional Context