CLOUDSTACK-2522: While processing agents behind on ping, we may fail to process a host that is already in 'Down' state
CLOUDSTACK-2522: While processing agents behind on ping, we may fail to process a host that is already in 'Down' state

Changes:
- Added a transition for DOWN -> DOWN state on PING TIMEOUT so that transition will set mgmt_server_id in the host table to null.

resmo/cloudstack,resmo/cloudstack,jcshen007/cloudstack,jcshen007/cloudstack,wido/cloudstack,GabrielBrascher/cloudstack,GabrielBrascher/cloudstack,DaanHoogland/cloudstack,resmo/cloudstack,mufaddalq/cloudstack-datera-driver,resmo/cloudstack,wido/cloudstack,GabrielBrascher/cloudstack,wido/cloudstack,DaanHoogland/cloudstack,mufaddalq/cloudstack-datera-driver,jcshen007/cloudstack,DaanHoogland/cloudstack,wido/cloudstack,jcshen007/cloudstack,wido/cloudstack,DaanHoogland/cloudstack,mufaddalq/cloudstack-datera-driver,jcshen007/cloudstack,GabrielBrascher/cloudstack,DaanHoogland/cloudstack,wido/cloudstack,wido/cloudstack,jcshen007/cloudstack,resmo/cloudstack,mufaddalq/cloudstack-datera-driver,resmo/cloudstack,resmo/cloudstack,mufaddalq/cloudstack-datera-driver,DaanHoogland/cloudstack,GabrielBrascher/cloudstack,DaanHoogland/cloudstack,GabrielBrascher/cloudstack,jcshen007/cloudstack,mufaddalq/cloudstack-datera-driver,GabrielBrascher/cloudstack