Fix header CTA link for Omnibus
As part of the TW monthly chores, I got a lot of hits for this page. Let's fix this old link first to help make the external broken link test more readable.
public/omnibus/update/gitlab_7_changes.html:
[ ERROR ] external_links - broken reference to https://about.gitlab.com/free-trial/self-managed/: link has moved permanently to 'https://about.gitlab.com/free-trial/#selfmanaged/'
public/omnibus/update/gitlab_8_changes.html:
[ ERROR ] external_links - broken reference to https://about.gitlab.com/free-trial/self-managed/: link has moved permanently to 'https://about.gitlab.com/free-trial/#selfmanaged/'
Related to technical-writing#474 (closed)
Edited by Amy Qualls