Merge request author can self-approve the request

Summary

I think the changes in https://gitlab.com/gitlab-org/gitlab-ee/issues/10441 broke the behavior of the approval flags. We have set the prevention of approval by the merge author in the settings, however, the merge author can still approve and merge.

Steps to reproduce

Open up a merge request and self-approve.

What is the current bug behavior?

Merge request author can approve their own request.

What is the expected correct behavior?

Approval should be prevented, if setting is set.

Relevant logs and/or screenshots

Settings	Still able to approve

Output of checks

(If you are reporting a bug on GitLab.com, write: This bug happens on GitLab.com)

Results of GitLab environment info

We're running 11.10

/label ~bug