Bugfix: projector defer computing localhost.

projector, if configured in colocated mode, shall find the colocated KV
service from ns_server's server-list. But this make sense only after a node
is joined to the cluster. Hence computing the local kv-service while starting
a new feed.

Change-Id: I7d2ec2d969db33a77586eb094a794672c09e2d39
Reviewed-on: http://review.couchbase.org/43439
Reviewed-by: Sarath Lakshman <sarath@couchbase.com>
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Tested-by: Pratap Chakravarthy <prataprc@couchbase.com>