[gtk+] gtk3-demo: Fix the modelbutton example

[Matthias Clasen <matthiasc src gnome org>]

commit c2534af15ef8e8fb1173d9e7501fe8e505471308
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Jun 19 22:56:20 2016 -0400

    gtk3-demo: Fix the modelbutton example
    
    The color menu buttons didn't have the necessary target property
    to be successfully activated.

 demos/gtk-demo/modelbutton.ui |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/demos/gtk-demo/modelbutton.ui b/demos/gtk-demo/modelbutton.ui
index a5a7255..8fbd90c 100644
--- a/demos/gtk-demo/modelbutton.ui
+++ b/demos/gtk-demo/modelbutton.ui
@@ -66,6 +66,7 @@
           <object class="GtkModelButton">
             <property name="visible">1</property>
             <property name="action-name">win.color</property>
+            <property name="action-target">'red'</property>
             <property name="text">Red</property>
             <property name="inverted">1</property>
           </object>
@@ -74,6 +75,7 @@
           <object class="GtkModelButton">
             <property name="visible">1</property>
             <property name="action-name">win.color</property>
+            <property name="action-target">'green'</property>
             <property name="text">Green</property>
             <property name="inverted">1</property>
           </object>
@@ -82,6 +84,7 @@
           <object class="GtkModelButton">
             <property name="visible">1</property>
             <property name="action-name">win.color</property>
+            <property name="action-target">'blue'</property>
             <property name="text">Blue</property>
             <property name="inverted">1</property>
           </object>