adtrust.py: mention restarting sssd when adding trust agents
After adding a replica to AD trust agent, the warning
message does not mention that restarting sssd is mantatory
for the trust agent to work. Fix the string.
Fixes: https://pagure.io/freeipa/issue/8148
Signed-off-by: François Cami <fcami@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>