[QA] Fix the 'clone using deploy key' tests

What does this MR do?

CSS class for the job logs has changed in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/22116/diffs as we're using Vue (app/assets/javascripts/jobs/components/job_log.vue) to render the logs now instead of app/views/shared/builds/_build_output.html.haml.

What are the relevant issue numbers?

Fixes https://gitlab.com/gitlab-org/quality/nightly/issues/26.

Does this MR meet the acceptance criteria?

• [-] Changelog entry added, if necessary
• [-] Documentation created/updated
• [-] Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides