wizard: listen for efreet build event, not update
wizard: listen for efreet build event, not update

build event signals cache exists, update that it has been updated. We
only want an existing cache here.

SVN revision: 79482

tizenorg/platform.upstream.enlightenment,tasn/enlightenment,FlorentRevest/Enlightenment,FlorentRevest/Enlightenment,FlorentRevest/Enlightenment,tasn/enlightenment,rvandegrift/e,rvandegrift/e,rvandegrift/e,tizenorg/platform.upstream.enlightenment,tizenorg/platform.upstream.enlightenment,tasn/enlightenment