Client subscriptions recreated when the client restart

[ishabani]

When a client restarts, the GOV susbcribes it as a platform subscriber for a topic
The creation of the subscription between DSB and EC shouldn't occure if this subscription exist already
However each time the client restarts and ask to be a platform subscriber, the number of subscriptions DSB -EC is multiplied by 4
To reproduce, run a lient for the first time, get notified once
stop the client
reun it again, you'll be notified 4 times
stop again and restart it , you'll be notified 16 times !!