[gnome-builder] stack-controls: add parent to the template ui element

[Sébastien Lafargue <slafargue src gnome org>]

commit 20334c9bba9266c45765e3f4f9fdbad8f856f57f
Author: Sebastien Lafargue <slafargue gnome org>
Date:   Wed Jul 26 20:02:33 2017 +0200

    stack-controls: add parent to the template ui element

 libide/editor/ide-editor-layout-stack-controls.ui |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/libide/editor/ide-editor-layout-stack-controls.ui 
b/libide/editor/ide-editor-layout-stack-controls.ui
index af07c68..1dcc2eb 100644
--- a/libide/editor/ide-editor-layout-stack-controls.ui
+++ b/libide/editor/ide-editor-layout-stack-controls.ui
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interface>
-  <template class="IdeEditorLayoutStackControls">
+  <template class="IdeEditorLayoutStackControls" parent="GtkBox">
     <property name="orientation">horizontal</property>
     <child>
       <object class="GtkButton" id="warning_button">