[gnome-calendar] date-chooser: Fix leak of GDateTime

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

commit 705d9809f9b02c88731b71ae82b2eaa0cd936998
Author: Victor Toso <me victortoso com>
Date:   Fri Sep 30 23:42:31 2016 +0200

    date-chooser: Fix leak of GDateTime
    
    264,180 (1,920 direct, 262,260 indirect) bytes in 60 blocks are definitely lost in loss record 18,487 of 
18,509
       at 0x4C2DB9D: malloc (vg_replace_malloc.c:299)
       by 0x9A0C90E: g_malloc (gmem.c:94)
       by 0x9A26A55: g_slice_alloc (gslice.c:1025)
       by 0x9A26A95: g_slice_alloc0 (gslice.c:1051)
       by 0x99E8DC4: g_date_time_alloc (gdatetime.c:428)
       by 0x99E95C1: g_date_time_new (gdatetime.c:957)
       by 0x99E97B2: g_date_time_new_local (gdatetime.c:1012)
       by 0x42481C: calendar_compute_days (gcal-date-chooser.c:150)
       by 0x425F3B: gcal_date_chooser_set_date (gcal-date-chooser.c:743)
       by 0x4251CD: multi_choice_changed (gcal-date-chooser.c:420)
       by 0x9567F16: g_cclosure_marshal_VOID__PARAM (gmarshal.c:1832)
       by 0x95638B9: g_closure_invoke (gclosure.c:804)
    
    https://bugzilla.gnome.org/show_bug.cgi?id=772272

 src/gcal-date-chooser-day.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/gcal-date-chooser-day.c b/src/gcal-date-chooser-day.c
index dc8671b..431ee2c 100644
--- a/src/gcal-date-chooser-day.c
+++ b/src/gcal-date-chooser-day.c
@@ -88,6 +88,7 @@ gcal_date_chooser_day_dispose (GObject *object)
   GcalDateChooserDay *self = GCAL_DATE_CHOOSER_DAY (object);
 
   g_clear_object (&self->multipress_gesture);
+  g_clear_pointer (&self->date, g_date_time_unref);
 
   G_OBJECT_CLASS (gcal_date_chooser_day_parent_class)->dispose (object);
 }