[gtk+] gtk-demo: include missing file on EXTRA_DIST

[Ignacio Casal Quinteiro <icq src gnome org>]

commit 1e10bbef260250f0167495766dedee4c5af6694a
Author: Ignacio Casal Quinteiro <icq gnome org>
Date:   Wed Jul 23 10:43:41 2014 +0200

    gtk-demo: include missing file on EXTRA_DIST

 demos/gtk-demo/Makefile.am |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/demos/gtk-demo/Makefile.am b/demos/gtk-demo/Makefile.am
index 62cd333..4eb3914 100644
--- a/demos/gtk-demo/Makefile.am
+++ b/demos/gtk-demo/Makefile.am
@@ -124,6 +124,7 @@ RESOURCES=  $(demos)                        \
                revealer.ui                     \
                theming.ui                      \
                listbox.ui                      \
+               popover.ui                      \
                alphatest.png                   \
                apple-red.png                   \
                brick.png                       \