delete vitrage.transformers section in setup.cfg
delete vitrage.transformers section in setup.cfg

section of vitrage.transformers is an old configuration
that we should delete

Fixes: bug #1579616

Change-Id: I3de785bb8d3cdf904dff5f6d8a10a4c80adb0a77
Signed-off-by: dongwenjuan <648f677d6c1326e8822df97fbbc7d15228521866@zte.com.cn>

openstack/vitrage,openstack/vitrage,openstack/vitrage