[Trivial] Use local conf instead of global conf
[Trivial] Use local conf instead of global conf

We have no global conf configured, when service is started, we
initialize a local object of cfg.ConfigOpt() instead of using
cfg.CONF. Acrossing whole Aodh project, there is only one place
still uses the global unconfigured conf object, that is zaqar.

This problem is not exposed early is because previously zaqar
register its options inside its module, hence it actually always
uses the default values, which is wrong but enough for test. After
patch I0f3b6b151fe71b25ed49d66f5c2bdecb11fb6f5f lands, it will
raise NoSuchOptError.

Let's fix this one, decision of global conf V.S. local conf can
be in another patch.

Change-Id: Ie05d778444f27f2dc07b4afb43c7037e66b3c331

openstack/aodh,openstack/aodh