[glibmm/glibmm-2-62] NEWS: Add a missing issue number

[Kjell Ahlstedt <kjellahl src gnome org>]

commit fe0861d51f0709b9059c874e099562d36bc74c81
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Wed Oct 9 16:12:25 2019 +0200

    NEWS: Add a missing issue number

 NEWS | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/NEWS b/NEWS
index a0a7d009..e57e9416 100644
--- a/NEWS
+++ b/NEWS
@@ -34,7 +34,7 @@ Gio:
 * Drive, MountOperation, ThemedIcon, TlsDatabase, VolumeMonitor:
   Fix ownership of some lists and arrays (Fixes memory leaks
   and dangling pointers)
-  (Kjell Ahlstedt)
+  (Kjell Ahlstedt) Issue #50 (Gary Wang)
 * Add SocketControlMessage::add_deserialize_func()
   (Kjell Ahlstedt) Issue #52 (Ankur deep jaiswal)