Don't render link when user login is nil

[blish-guenzler]

When user login is nil, Rails renders the URL as link text instead. To avoid this, the link is only rendered when user.login is present.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.62%. Comparing base (4c5faf7) to head (4f6ecc0).
⚠️ Report is 19 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #259   +/-   ##
=======================================
  Coverage   98.62%   98.62%           
=======================================
  Files          11       11           
  Lines         291      291           
=======================================
  Hits          287      287           
  Misses          4        4           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[alchemycms-bot]

💚 All backports created successfully

Status	Branch	Result
✅	8.0-stable
✅	8.1-stable

Questions ?

Please refer to the Backport tool documentation and see the Github Action logs for details