[gnome-todo] task: use g_clear_pointer

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 8b7324edce4b1645b4d3e3ace6fa43f537a6c40c
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Wed Oct 5 22:14:00 2016 -0300

    task: use g_clear_pointer

 src/gtd-task.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)
---
diff --git a/src/gtd-task.c b/src/gtd-task.c
index 062785f..4cb28f3 100644
--- a/src/gtd-task.c
+++ b/src/gtd-task.c
@@ -728,8 +728,7 @@ gtd_task_set_due_date (GtdTask   *task,
         g_object_notify (G_OBJECT (task), "due-date");
     }
 
-  if (current_dt)
-    g_date_time_unref (current_dt);
+  g_clear_pointer (&current_dt, g_date_time_unref);
 }
 
 /**