Fix rails console

What does this MR do?

In !26924 (merged) (just merged), Gitlab::Shell#version was promoted to class-level. However, I missed one caller of it! Now rails console is broken :S.

This MR should fix it.

Do you mind looking since you were maintainer for the introducing MR, @jarka ?

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content