Unable to use Azure Workbench or workbench APIs after newly deploying it(Build1.8.1).

### Description
Unable to use Azure Workbench or workbench APIs after newly deploying it(Build1.8.1). We are getting CORS error when we debug in web console. NOTE: We have the same application working as expected in 1.8 version.

Unable to access swagger API through Postman as well.
https://docs.microsoft.com/en-us/answers/questions/33132/unable-to-use-azure-workbench-or-workbench-apis-af.html

### This issue is for a: (mark with an `x`)
```
- [ ] bug report -> please search issues before submitting
- [ ] feature request
- [ ] documentation issue or request
- [x ] regression (a behavior that used to work and stopped in a new release)
```

### Minimal steps to reproduce
Deploy the workbench on build 1.8.1
### Any log messages given by the failure
CORS error on Azure workbench UI. Azure workbench UI is not able to communicate with swagger API

### Expected/desired behavior
Azure Workbench UI should be able to communicate with swagger API

### OS and Version?
> Windows 10

### Versions
> Build 1.8.1

### Mention any other details that might be useful
Error Logs on UI console:

Access to XMLHttpRequest at 'https://XXXXXX.azurewebsites.net/api/v2/users?sortBy=FirstName&top=50&skip=0' from origin 'https://XXXX.azurewebsites.net' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.