Message about prioritized labels on project labels for non-member

Summary

A message about prioritized labels on project labels is shown for non-member, which should be hidden.

Steps to reproduce

1. Make sure logged out from your GitLab and have access to https://gitlab.com/gitlab-org/gitlab-ce/labels in your browser to see this message.

What is the current bug behavior?

Anyone can see this message for prioritized label.

What is the expected correct behavior?

Only users who can prioritize labels on their project should see this message to star/prioritize labels.

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com (since 8.9 (see !4652 (merged)) through 9.4.0-rc3).

Possible fixes

Hide the message when a non-member has an access to the labels page.