correctly prettify exclusive owner dissappearance warning
WRONG: Queue "queue 'amq.gen-FQZtyp6mpRdmm3-on_LAOQ' in vhost 'urhyfncz'"
exclusive owner went away
RIGHT: exclusive owner for queue 'amq.gen-FQZtyp6mpRdmm3-on_LAOQ' in
vhost 'urhyfncz' went away

This got broken in http://hg.rabbitmq.com/rabbitmq-server/rev/f9f4919656ab
merge stable into default