Bug fix for UpdateStreamRequest and StreamReader

- Send endpoints in UpdateStreamRequest
- Initialize worker channels in streamReader

Change-Id: If370fece359fbfea4ad5ca1c94e7d03cf763f37f
Reviewed-on: http://review.couchbase.org/38883
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Reviewed-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>
Tested-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>