GtkAssistant pages does not remember `Has padding` property

The Has padding page property of GtkAssistant widget seems to not be set by Glade in .ui files.

Steps to reproduce

1. Create .ui file in Glade with default GtkAssitant widget
2. Run example in Glade or in executable

Current behavior

Every time .ui file is load again an then launched, Has padding is not set/reset to false.

Before reload:

After reload:

Expected outcome

Remember Has padding property state.

Version information

• GTK3: 3.24.26
• Glade: 3.38.2
• OS: Manjaro Linux

Additional information

Glade .ui source code:

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.38.2 -->
<interface>
  <requires lib="gtk+" version="3.24"/>
  <template class="__glade_unnamed_1" parent="GtkAssistant">
    <property name="can-focus">False</property>
    <property name="title" translatable="yes">Example Assistant</property>
    <property name="modal">True</property>
    <property name="destroy-with-parent">True</property>
    <property name="icon-name">application-x-executable</property>
    <child>
      <object class="GtkBox" id="page_1">
        <property name="visible">True</property>
        <property name="can-focus">False</property>
        <property name="orientation">vertical</property>
        <child>
          <object class="GtkLabel">
            <property name="visible">True</property>
            <property name="can-focus">False</property>
            <property name="label" translatable="yes">Example</property>
            <attributes>
              <attribute name="size" value="65536"/>
            </attributes>
          </object>
          <packing>
            <property name="expand">True</property>
            <property name="fill">True</property>
            <property name="position">0</property>
          </packing>
        </child>
      </object>
      <packing>
        <property name="page-type">intro</property>
        <property name="title" translatable="yes">Introduction</property>
        <property name="complete">True</property>
      </packing>
    </child>
    <child internal-child="action_area">
      <object class="GtkBox">
        <property name="can-focus">False</property>
        <property name="halign">end</property>
        <property name="margin-start">6</property>
        <property name="margin-end">6</property>
        <property name="margin-top">6</property>
        <property name="margin-bottom">6</property>
        <property name="spacing">6</property>
      </object>
      <packing>
        <property name="has-padding">False</property>
      </packing>
    </child>
  </template>
</interface>