Catch missing SQLLocation

[kaapstorm]

Technical Summary

Resolves this Sentry error.

This function is used in two places. Both places already check whether it returned None.

(One of those places is the clean() method on a model, and that seems fine. But the other place fetches the latest enabled build for a user based on their location. So this error means that there is a user out there assigned to a location that doesn't exist. I will follow up.)

Safety Assurance

Safety story

Catches an uncaught exception, and returns a valid return value instead.

Automated test coverage

Not covered by automated tests.

QA Plan

QA not planned.

Rollback instructions

• This PR can be reverted after deploy with no further considerations

Labels & Review

• Risk label is set correctly
• The set of people pinged as reviewers is appropriate for the level of risk of the change

[mkangia]

Thank you.

When I wrote this function 5 years ago, I wasn't able to foresee this.