If all agents are shown as a standby it is possible changing state
were lost due to problems with RabbitMQ. Current change adds check
for ha state in fetch_and_sync_all_routers. If state is different -
notify server that state should be changed.
Also change _get_bindings_and_update_router_state_for_dead_agents
to set standby for dead agent only in case we have more than one
active.
Change-Id: If5596eb24041ea9fae1d5d2563dcaf655c5face7
Closes-bug:#1648242