Expand the comment about ns_config:do_update_rec.
Expand the comment about ns_config:do_update_rec.

Change-Id: I3820ea2da129474461b1d781b2d369d3d6821db9
Reviewed-on: http://review.couchbase.org/39542
Tested-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>

membase/ns_server,membase/ns_server,t3rm1n4l/ns_server,mschoch/ns_server,membase/ns_server,ceejatec/ns_server,t3rm1n4l/ns_server,membase/ns_server,mschoch/ns_server,nimishzynga/ns_server,ceejatec/ns_server,nimishzynga/ns_server,ceejatec/ns_server,ceejatec/ns_server,t3rm1n4l/ns_server,nimishzynga/ns_server,mschoch/ns_server,ceejatec/ns_server,membase/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,ceejatec/ns_server,mschoch/ns_server,t3rm1n4l/ns_server,nimishzynga/ns_server,mschoch/ns_server,mschoch/ns_server,membase/ns_server,t3rm1n4l/ns_server