Tooltips not showing up for scoped labels on issue activity

Summary

Tooltips are not rendering for issue activity feed scoped labels. pajamasintegrate

Steps to reproduce

Visit #263714 (closed) and hover over scoped labels in issue activity

Example Project

#263714 (closed)

What is the current bug behavior?

Tooltips do not show up

What is the expected correct behavior?

Tooltips should show up

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)
(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)
(we will only investigate if the tests are passing)

Possible fixes