[pygobject] Update NEWS

[Christoph Reiter <creiter src gnome org>]

commit 4b92d6d1d92b711f3640238504b9714a7d89ea29
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Thu May 31 17:12:18 2018 +0200

    Update NEWS

 NEWS | 9 +++++++++
 1 file changed, 9 insertions(+)
---
diff --git a/NEWS b/NEWS
index fc879176..e617a65d 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,12 @@
+3.28.3 - 2018-05-31
+-------------------
+
+* Fix Gio.Application leak in case no signal handler is set before.
+  :issue:`219`
+* Squash critical warning when using array as hash value
+  (:user:`Philip Withnall <pwithnall>`)
+
+
 3.29.2 - 2018-05-16
 -------------------