In case of ovsdb -all job, topology tree will have

In case of ovsdb -all job, topology tree will have
multiple topology in the config and operational data store
because multiple features are installed and most of the features
like bgp,netconf,hwvtep:1,sxp will initialize their topology.
So matching on {network-topology:{topology:[{topology-id:ovsdb:1}]}}
for checking if ovsdb:1 topology is empty will always fail.
We should only check if the ovsdb:1 topology is empty or not.
This patch fixes the matching issue.

Change-Id: Id37e62c30e02ebb0299d284261ec029072a255ce
Signed-off-by: Anil Vishnoi <vishnoianil@gmail.com>