[gnome-control-center] Add a note to POTFILES.in about the gvc submodule

[Piotr Drąg <piotrdrag src gnome org>]

commit ea73c40d5f03c424b1e6946c3b621eacd99aec75
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Sun Apr 14 21:54:12 2013 +0200

    Add a note to POTFILES.in about the gvc submodule

 po/POTFILES.in | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/po/POTFILES.in b/po/POTFILES.in
index d141b04..8038e92 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -159,6 +159,7 @@ panels/sound/data/sounds/gnome-sounds-default.xml.in.in
 panels/sound/gvc-balance-bar.c
 panels/sound/gvc-channel-bar.c
 panels/sound/gvc-combo-box.c
+# Please do not remove this file from POTFILES.in. Run "git submodule init && git submodule update" to get 
it.
 panels/sound/gvc/gvc-mixer-control.c
 panels/sound/gvc-mixer-dialog.c
 panels/sound/gvc-sound-theme-chooser.c