Fixed OVSvApp L2 agent restart issues
Fixed OVSvApp L2 agent restart issues

1. Fixed recover_physical_bridges() method
2. Fixed _remove_stale_ports_flows() method

Change-Id: I9d1aba095fb81dbe1c618f69a51a0812c6825c17
Closes-Bug: #1487850

ekosareva/vmware-dvs,ekosareva/networking-vsphere,Mirantis/vmware-dvs,ekosareva/vmware-dvs,openstack/networking-vsphere,openstack/networking-vsphere,stackforge/networking-vsphere,Mirantis/vmware-dvs,VTabolin/networking-vsphere,VTabolin/networking-vsphere,stackforge/networking-vsphere,ekosareva/networking-vsphere