[mutter] Update POTFILES.in

[Piotr Drąg <piotrdrag src gnome org>]

commit 22978b9d07328f98a515dda30edd16e122b992e7
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Fri Jun 28 19:10:39 2019 +0200

    Update POTFILES.in

 po/POTFILES.in | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/po/POTFILES.in b/po/POTFILES.in
index aea3b7c50..789e7225e 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -8,6 +8,7 @@ data/mutter.desktop.in
 data/org.gnome.mutter.gschema.xml.in
 data/org.gnome.mutter.wayland.gschema.xml.in
 src/backends/meta-input-settings.c
+src/backends/meta-monitor.c
 src/backends/meta-monitor-manager.c
 src/backends/meta-profiler.c
 src/compositor/compositor.c