[gnome-control-center] sound: Remove reference to unused widget

[Robert Ancell <rancell src gnome org>]

commit ea22446ad1a03118196e7e5c92dbe88865d8b358
Author: Robert Ancell <robert ancell canonical com>
Date:   Tue Nov 12 14:31:14 2019 +1300

    sound: Remove reference to unused widget

 panels/sound/cc-sound-panel.c  | 2 --
 panels/sound/cc-sound-panel.ui | 2 +-
 2 files changed, 1 insertion(+), 3 deletions(-)
---
diff --git a/panels/sound/cc-sound-panel.c b/panels/sound/cc-sound-panel.c
index b73e173c9..7a7e20b7d 100644
--- a/panels/sound/cc-sound-panel.c
+++ b/panels/sound/cc-sound-panel.c
@@ -58,7 +58,6 @@ struct _CcSoundPanel
   GtkListBoxRow     *input_profile_row;
   CcVolumeSlider    *input_volume_slider;
   GtkSizeGroup      *label_size_group;
-  GtkBox            *main_box;
   CcDeviceComboBox  *output_device_combo_box;
   GtkListStore      *output_device_model;
   CcLevelBar        *output_level_bar;
@@ -205,7 +204,6 @@ cc_sound_panel_class_init (CcSoundPanelClass *klass)
   gtk_widget_class_bind_template_child (widget_class, CcSoundPanel, input_profile_row);
   gtk_widget_class_bind_template_child (widget_class, CcSoundPanel, input_volume_slider);
   gtk_widget_class_bind_template_child (widget_class, CcSoundPanel, label_size_group);
-  gtk_widget_class_bind_template_child (widget_class, CcSoundPanel, main_box);
   gtk_widget_class_bind_template_child (widget_class, CcSoundPanel, output_device_combo_box);
   gtk_widget_class_bind_template_child (widget_class, CcSoundPanel, output_level_bar);
   gtk_widget_class_bind_template_child (widget_class, CcSoundPanel, output_list_box);
diff --git a/panels/sound/cc-sound-panel.ui b/panels/sound/cc-sound-panel.ui
index 31175cff6..588c578d8 100644
--- a/panels/sound/cc-sound-panel.ui
+++ b/panels/sound/cc-sound-panel.ui
@@ -17,7 +17,7 @@
             <property name="margin_start">12</property>
             <property name="margin_end">12</property>
             <child>
-              <object class="GtkBox" id="main_box">
+              <object class="GtkBox">
                 <property name="visible">True</property>
                 <property name="orientation">vertical</property>
                 <property name="spacing">12</property>