Hide Site Name menu if the user isn't a member and isn't a super admin. Always...

Hide Site Name menu if the user isn't a member and isn't a super admin. Always show My Sites if the user has a site, and don't remove the current site from the list. Fixes #19122.


git-svn-id: https://core.svn.wordpress.org/trunk@19184 1a063a9b-81f0-0310-95a4-ce76da25c4cd