Bug(sponsors): When creating a new sponsor app the first contact should default to the primary

[JacobCoffee]

Describe the bug

New sponsors form fails due to missed checkbox

To Reproduce

1. Create sponsorship application
2. Once you enter into, submit
3. Be met with angry form invalidation:
   

Expected behavior

The first contact is usually going to be the primary. By defaulting this to checked we save some annoyance and headache for users having to reupload images because they forgot to click the box.

URL to the issue

pythondotorg/sponsors/models/sponsors.py

Line 154 in 096ac33

primary = models.BooleanField(

Screenshots

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Browsers

Other

Operating System

Other

Browser Version

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Relevant log output

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Additional context

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[SDprogramer]

Is this issue still open or it is fixed by other members please tell. If not then i want to fix it. I will tell the approach clearly.