Clear existing streams from upr client if updater crash

If updater crash due to some reason, the next updater run
should not be affected. If updater crashes while reading from
a upr stream, the upr stream request will be active within the
upr client. We need to remove the active stream if updater exits
with an error.

Change-Id: I36ee7bf3ef7673cab2547762db7e3db5ae18c355
Reviewed-on: http://review.couchbase.org/38480
Reviewed-by: Volker Mische <volker.mische@gmail.com>
Tested-by: Sarath Lakshman <sarath@couchbase.com>

src/couch_set_view/src/couch_set_view_group.erl

@@ -1249,6 +1249,7 @@ handle_info({'EXIT', Pid, {updater_error, Error}}, #state{updater_pid = Pid, gro
         updater_state = not_running,
         update_listeners = Listeners2
     },
+    stop_upr_streams(State),
     ?inc_updater_errors(State2#state.group),
     case State#state.shutdown of
     true ->