[gnome-control-center] Update POTFILES.in

[Piotr Drąg <piotrdrag src gnome org>]

commit bd35ffc31193fdd30b3a0b07499d67289e449113
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Fri May 31 20:45:59 2019 +0200

    Update POTFILES.in

 po/POTFILES.in | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 0c6fdd8e1..6eb3ea01b 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -4,10 +4,12 @@ panels/applications/cc-applications-panel.c
 panels/applications/cc-applications-panel.ui
 panels/applications/gnome-applications-panel.desktop.in.in
 panels/background/bg-colors-source.c
-panels/background/cc-background-chooser-dialog.c
+panels/background/cc-background-chooser.c
+panels/background/cc-background-chooser.ui
 panels/background/cc-background-item.c
 panels/background/cc-background-panel.c
 panels/background/cc-background-panel.ui
+panels/background/cc-background-preview.ui
 panels/background/gnome-background-panel.desktop.in.in
 panels/bluetooth/cc-bluetooth-panel.c
 panels/bluetooth/cc-bluetooth-panel.ui