[pitivi] Update POTFILES.in

[Piotr Drąg <piotrdrag src gnome org>]

commit 11ee8665c373b64943ba1ee44bb330acaa0018bf
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Tue Aug 29 18:50:50 2017 +0200

    Update POTFILES.in

 po/POTFILES.in |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/po/POTFILES.in b/po/POTFILES.in
index e6e6d2e..284eda3 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -26,6 +26,7 @@ pitivi/effects.py
 pitivi/mainwindow.py
 pitivi/mediafilespreviewer.py
 pitivi/medialibrary.py
+pitivi/pluginmanager.py
 pitivi/preset.py
 pitivi/project.py
 pitivi/render.py