More strict current-user editing checks in `BP_Members_Admin->profile_admin_head()`.

Fixes bug causing "Your Profile" menu item to be selected when "Users" should be. Fixes #5978.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@9115 cdf35c40-ae34-48e0-9cc9-0c9da1808c22