Undismissable "you can also press cmd+enter" tooltip

Summary

When performing a code review, if I type tab + spacebar to submit a comment, there's no way to dismiss the tooltip that says "you can also press cmd+enter"

Steps to reproduce

Open a merge request. Type a comment on any line, press Tab to highlight the Comment field, then press space bar to submit the comment. Depending on your computer, you may need to change the accessibility option so Tab highlights all fields, not just text boxes.

What is the current bug behavior?

A tooltip appears that says "You can also press Cmd+Enter"

What is the expected correct behavior?

I should be able to dismiss the tooltip. Instead, the tooltip hovers on the screen until I refresh the page.

Relevant logs and/or screenshots

Results of GitLab environment info

Gitlab 9.4.2-ee, https://gitlab.com/gitlab-org/gitlab-ee/commits/421b9b5.