Fixes security harness check

What does this MR do?

Fixes security harness check.

It seems bash was not picking up the conditional because of missing space around the square brackets

Before with the security harness on

❯ git push dev test-mc-security-branch
Enumerating objects: 5, done.
Counting objects: 100% (5/5), done.
Delta compression using up to 12 threads
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 274 bytes | 137.00 KiB/s, done.
Total 3 (delta 1), reused 0 (delta 0)
remote:
remote: To create a merge request for test-mc-security-branch, visit:
remote:   https://dev.gitlab.org/gitlab/gitlab-ee/-/merge_requests/new?merge_request%5Bsource_branch%5D=test-mc-security-branch
remote:
To dev.gitlab.org:gitlab/gitlab-ee.git
   18af1cfa83a..14fd65d00a0  test-mc-security-branch -> test-mc-security-branch

After with the security harness on

❯ git push dev test-mc-security-branch
Pushing to remotes other than gitlab.com/gitlab-org/security has been disabled!
Run scripts/security-harness to disable this check.

error: failed to push some refs to 'git@dev.gitlab.org:gitlab/gitlab-ee.git'

❯ git push origin test-mc-security-branch
Pushing to remotes other than gitlab.com/gitlab-org/security has been disabled!
Run scripts/security-harness to disable this check.

error: failed to push some refs to 'git@gitlab.com:gitlab-org/gitlab.git'

Related to gitlab-com/gl-infra/delivery#692 (closed)

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

Availability and Testing

• [-] Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done