Part 2 of Fix Redirect Github Free for Teams URL

Follow up fix for !46518 (closed) (Add redirect for github-free-for-teams from https://about.gitlab.com/blog/2020-04-14-github-free-for-teams/ to https://about.gitlab.com/blog/2020/04/14/github-free-for-teams/). If there is a slash on the end of the redirected URL, it redirects to a double-slash on the end and 404's

relates #7155 (closed)