Fix visually broken admin dashboard

Until a license is added GitLab EE, the admin dashboard is visually
broken because of an incorrect container size.

app/views/dashboard/projects/_zero_authorized_projects.html.haml

 - admin_without_ee_license = !current_license && current_user.admin?
 
 .blank-state-parent-container{ class: ('has-start-trial-container' if admin_without_ee_license) }
-  .section-container.section-welcome{ class: ('col-md-6' if admin_without_ee_license) }
+  .section-container.section-welcome
     .container.section-body
       .row
         .blank-state-welcome

changelogs/unreleased-ee/jramsay-4661-fix-admin-dashboard.yml

+---
+title: Fix visually broken admin dashboard until license is added
+merge_request: 4196
+author:
+type: fixed