Ticket 49320 - Activating already active role returns error 16
Bug Description: ns-activate.pl returns error 16 when trying to activate an
already active role.
Fix Description: Check for error 16 (no such attr), and return error 100.
Also added a "redirect"otion to the ldapmod function to
hide any errors printed to STDERR, so that the script can
display its own error message.
Reviewed by: firstyear(Thanks!)
(cherry picked from commit 406084847f29aa44ffd81de746770aeff6b67c61)