Fix gnocchi-metricd shutdown
Fix gnocchi-metricd shutdown

gnocchi-metricd does not shutdown gracefully because we block on
metric queue.get(). This change adds a timeout to allow the process
to terminate every 10 seconds.

Change-Id: Id7917464009b19a0e27ff84694803f97f43cfac7

leandroreox/gnocchi,sileht/gnocchi,leandroreox/gnocchi,gnocchixyz/gnocchi,gnocchixyz/gnocchi,sileht/gnocchi