[libhandy] preferences-group: Protect against gtk_widget_show_all()

[Adrien Plazas <aplazas src gnome org>]

commit 544c608017ea5b9435b5114cc5b5496f1f52bcc4
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Thu Dec 17 18:11:44 2020 +0500

    preferences-group: Protect against gtk_widget_show_all()
    
    A bunch of internal widgets were invisible but missing no-show-all.

 src/hdy-preferences-group.ui | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/src/hdy-preferences-group.ui b/src/hdy-preferences-group.ui
index 60a5ae1c..c8656077 100644
--- a/src/hdy-preferences-group.ui
+++ b/src/hdy-preferences-group.ui
@@ -13,6 +13,7 @@
             <property name="ellipsize">end</property>
             <property name="halign">start</property>
             <property name="xalign">0</property>
+            <property name="no-show-all">True</property>
             <style>
               <!-- Requires Adwaita from GTK 3.24.14. -->
               <class name="heading"/>
@@ -27,6 +28,7 @@
             <property name="halign">start</property>
             <property name="wrap">True</property>
             <property name="xalign">0</property>
+            <property name="no-show-all">True</property>
             <style>
               <class name="dim-label"/>
             </style>