When opening vector layer form properties, immediately expand

all drag-and-drop form containers

Otherwise it's really annoying to have to do this manually
all the time!

src/gui/vector/qgsattributesformproperties.cpp

@@ -572,6 +572,9 @@ QTreeWidgetItem *QgsAttributesFormProperties::loadAttributeEditorTreeItem( QgsAt
     }
   }
 
+  if ( newWidget )
+    newWidget->setExpanded( true );
+
   return newWidget;
 }