Health Status Edit button not visible in DarkMode

Summary

When in Dark Mode, the Edit link is not visible for setting Health Status in an Issue

Steps to reproduce

1. Set your preferences to Dark Mode (alpha)
2. Navigate to an issue
3. Notice that the Edit link is not visible as it is black text on a dark background whereas the other Edit links are white text on the dark background

Example Project

n/a -- you can see this in any project, including GitLab itself

What is the current bug behavior?

Currently the text is not visible, but it is functional if you know it is there and where to click

What is the expected correct behavior?

Text for the Edit link should be white (or same color as the others in the Issue bar on the right-side when viewing an issue

Possible fixes