[BUG] : Virtuals conflict with populate field with in bootcamp advanced result

[ballyalley-o]

Describe the bug Conflict with virtuals that doesn't have a data, i.e. course populate with for bootcamps that doesnt have courses.

To Reproduce Steps to reproduce the behavior:

1. Run the client
2. Click on 'view all bootcamps'
3. Scroll down to 'send a GET request'
4. See error

Expected behavior should return requested entity/ies

this results to broken pipe. and crash the server.

Screenshots

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context Add any other context about the problem here.