[gtk] Update POTFILES.in

[Piotr Drąg <piotrdrag src gnome org>]

commit 4feb88e2a4120b20ff04d5815c223cdaffecdb07
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Mon Feb 11 22:27:57 2019 +0100

    Update POTFILES.in

 po-properties/POTFILES.in | 1 +
 po/POTFILES.in            | 1 +
 2 files changed, 2 insertions(+)
---
diff --git a/po-properties/POTFILES.in b/po-properties/POTFILES.in
index f5d226f132..3eddc5a1bc 100644
--- a/po-properties/POTFILES.in
+++ b/po-properties/POTFILES.in
@@ -259,6 +259,7 @@ gtk/gtkshortcutssection.c
 gtk/gtkshortcutsshortcut.c
 gtk/gtkshortcutswindow.c
 gtk/gtksidebarrow.c
+gtk/gtksingleselection.c
 gtk/gtksizegroup.c
 gtk/gtkslicelistmodel.c
 gtk/gtksortlistmodel.c
diff --git a/po/POTFILES.in b/po/POTFILES.in
index fac6870b44..0ddee284f7 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -261,6 +261,7 @@ gtk/gtkshortcutssection.c
 gtk/gtkshortcutsshortcut.c
 gtk/gtkshortcutswindow.c
 gtk/gtksidebarrow.c
+gtk/gtksingleselection.c
 gtk/gtksizegroup.c
 gtk/gtksizerequest.c
 gtk/gtkslicelistmodel.c