[gtkmm-documentation] Builder examples: Remove can_default from the .glade files

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 54d35fee2a957f62021104be4869f712d07fd9c1
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Wed May 22 13:35:17 2019 +0200

    Builder examples: Remove can_default from the .glade files

 examples/book/builder/basic/basic.glade     | 1 -
 examples/book/builder/derived/derived.glade | 1 -
 2 files changed, 2 deletions(-)
---
diff --git a/examples/book/builder/basic/basic.glade b/examples/book/builder/basic/basic.glade
index d840b5d..37adeef 100644
--- a/examples/book/builder/basic/basic.glade
+++ b/examples/book/builder/basic/basic.glade
@@ -19,7 +19,6 @@
               <object class="GtkButton" id="quit_button">
                 <property name="label">_Quit</property>
                 <property name="can_focus">True</property>
-                <property name="can_default">True</property>
                 <property name="receives_default">False</property>
                 <property name="use_underline">True</property>
               </object>
diff --git a/examples/book/builder/derived/derived.glade b/examples/book/builder/derived/derived.glade
index c31d9a1..9f34638 100644
--- a/examples/book/builder/derived/derived.glade
+++ b/examples/book/builder/derived/derived.glade
@@ -19,7 +19,6 @@
               <object class="GtkButton" id="quit_button">
                 <property name="label">_Quit</property>
                 <property name="can_focus">True</property>
-                <property name="can_default">True</property>
                 <property name="receives_default">False</property>
                 <property name="use_underline">True</property>
               </object>