[gnome-builder] build: fix make check

[Christian Hergert <chergert src gnome org>]

commit 9ee51202eb121e580a3d69893293d41aa535c088
Author: Christian Hergert <christian hergert me>
Date:   Sun Apr 24 18:45:57 2016 -0700

    build: fix make check

 po/POTFILES.in |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 0212618..0924e13 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -141,3 +141,4 @@ plugins/terminal/gb-terminal-workbench-addin.c
 [type: gettext/glade]plugins/terminal/gtk/menus.ui
 plugins/todo/todo_plugin/__init__.py
 plugins/vala-pack/ide-vala-preferences-addin.vala
+plugins/hello-cpp/hellocppapplicationaddin.cc