In case if we are migrating a session leader task with a solely
slave peer we should not try to restore a group on the terminal
but rather simply inherit it, because a session of the group of
the inherited terminal is not the same as a session of our leader
thus kernel refuse to set any different group here.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>