[gnome-control-center] Update POTFILES.in

[Piotr Drąg <piotrdrag src gnome org>]

commit 1e6e77e07d3f532beefd9b2b8af910beed141335
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Fri Jun 17 12:54:54 2022 +0200

    Update POTFILES.in

 po/POTFILES.in | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 791b2533b..f30a03a60 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -216,7 +216,9 @@ panels/sound/cc-fade-slider.ui
 panels/sound/cc-output-test-dialog.c
 panels/sound/cc-output-test-dialog.ui
 panels/sound/cc-sound-panel.ui
+panels/sound/cc-subwoofer-slider.ui
 panels/sound/cc-volume-slider.c
+panels/sound/cc-volume-slider.ui
 panels/sound/gnome-sound-panel.desktop.in.in
 panels/thunderbolt/cc-bolt-device-dialog.c
 panels/thunderbolt/cc-bolt-device-dialog.ui