[gimp] Update POTFILES.in

[Piotr Drąg <piotrdrag src gnome org>]

commit 0968618590ed35465e46a2ee42cee24c972ce373
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Tue Jul 3 17:15:57 2018 +0200

    Update POTFILES.in

 po/POTFILES.in | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 5754e6fcc9..ba4fb796e2 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -103,6 +103,8 @@ app/core/gimp-batch.c
 app/core/gimp-contexts.c
 app/core/gimp-data-factories.c
 app/core/gimp-edit.c
+app/core/gimpextension.c
+app/core/gimpextensionmanager.c
 app/core/gimp-gradients.c
 app/core/gimp-gui.c
 app/core/gimp-internal-data.c