[tracker/wip/jfelder/tracker-notifier-annotation] tracker-notifier: Fix tracker_notifier_signal_subscribe annotation

[Jean Felder <jfelder src gnome org>]

commit 45caadadbe05fc35ec999cfb49941a3ba44ba7b9
Author: Jean Felder <jean felder gmail com>
Date:   Thu Nov 12 13:57:36 2020 +0100

    tracker-notifier: Fix tracker_notifier_signal_subscribe annotation

 src/libtracker-sparql/tracker-notifier.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/libtracker-sparql/tracker-notifier.c b/src/libtracker-sparql/tracker-notifier.c
index 6e2989bf8..38e6897fe 100644
--- a/src/libtracker-sparql/tracker-notifier.c
+++ b/src/libtracker-sparql/tracker-notifier.c
@@ -787,8 +787,8 @@ tracker_notifier_init (TrackerNotifier *notifier)
  * @notifier: a #TrackerNotifier
  * @connection: a #GDBusConnection
  * @service: DBus service name to subscribe to events for
- * @object_path: DBus object path to subscribe to events for, or %NULL
- * @graph: graph to listen events for, or %NULL
+ * @object_path: (nullable): DBus object path to subscribe to events for, or %NULL
+ * @graph: (nullable): graph to listen events for, or %NULL
  *
  * Listens to notification events from a remote SPARQL endpoint as a DBus
  * service (see #TrackerEndpointDBus). If the @object_path argument is