Tests: Fix database error in test_bp_last_activity_migrate() test.

The prepare()  method was missing the seventh parameter.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8693 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Add brackets to `bp-messages-screens.php`.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8694 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Move message sending out of comparison in `messages_screen_compose()`.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8695 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Replace `$bp` global touches in `messages_screen_compose()` with calls to `bp_get_messages_slug()`.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8696 cdf35c40-ae34-48e0-9cc9-0c9da1808c22