[gnome-todo] plugin-dialog: Initialize with back button hidden

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 886c4fe298442c2f4c0aa46865cbe62d05c320f4
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Mon Sep 17 01:08:06 2018 -0300

    plugin-dialog: Initialize with back button hidden
    
    The back button should only be visible when opening the
    preferences panel of any plugin. For that, we were simply
    not setting the visibility of the widget. That used to
    work on GTK3 because widgets were hidden by default, but
    this assumption is wrong on GTK4.

 data/ui/plugin-dialog.ui | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/data/ui/plugin-dialog.ui b/data/ui/plugin-dialog.ui
index b6184a8..1eb3abc 100644
--- a/data/ui/plugin-dialog.ui
+++ b/data/ui/plugin-dialog.ui
@@ -63,12 +63,12 @@
     </child>
     <child type="titlebar">
       <object class="GtkHeaderBar" id="headerbar">
-        <property name="visible">True</property>
         <property name="can_focus">False</property>
         <property name="title" translatable="yes">Extensions</property>
         <property name="show-title-buttons">True</property>
         <child>
           <object class="GtkButton" id="back_button">
+            <property name="visible">False</property>
             <property name="can_focus">True</property>
             <signal name="clicked" handler="back_button_clicked" object="GtdPluginDialog" swapped="no" />
             <child>