Fix memory leaks image case study link

[parlough]

Description of what this PR is changing or adding, and why: The null safe modifier was removed from the repo location causing the old link to fail.

Issues fixed by this PR (if any): Fixes #7836

Presubmit checklist

• This PR doesn’t contain automatically generated corrections (Grammarly or similar).
• This PR follows the Google Developer Documentation Style Guidelines — for example, it doesn’t use i.e. or e.g., and it avoids I and we (first person).
• This PR uses semantic line breaks of 80 characters or fewer.

[khanhnwin]

Thanks x2 @parlough!