Fix outdated MR security warning message

This is a fix for a bug related to #4913 (closed). This was introduced in the MR - !20954 (merged)

What does this MR do?

The cause of the issue looks like gl.mrWidgetData.diverged_commits_count value which is used to identify an outdated MR is undefined for gitlab.com. But it actually works fine on my local environment 🤔

To fix that, this MR avoids using gl object at all.

The actual reason could be a timing issue due to which the value is not being set.

Conformity

• Changelog entry