Don't restart event handler on termiation

COUCHDB-2561
diff --git a/src/couch_event_os_sup.erl b/src/couch_event_os_sup.erl
index 2a1457b..6c2b787 100644
--- a/src/couch_event_os_sup.erl
+++ b/src/couch_event_os_sup.erl
@@ -60,6 +60,7 @@
 handle_config_change(_, _, _, _, _) ->
     {ok, nil}.
 
+handle_config_terminate(_, stop, _) -> ok;
 handle_config_terminate(_, _, _) ->
     spawn(fun() ->
         timer:sleep(5000),