This patch transforms the add user link in the db privilege specific tab.
Instead of changing the tab, a Popup appear like in the normal privilege tab.
This patch produces this message in the generated popup:
Notice in ./server_privileges.php#1389
Undefined variable: _add_user_error
This Tracker item was closed automatically by the system. It was
previously set to a Pending status, and the original submitter
did not respond within 14 days (the time period specified by
the administrator of this Tracker).