Make notebook content redraw during drag

The extra condition here that caused the current child to
not redraw during reordering was introduced in f383e1f1
during the port to ::draw, but was not explained in the
commit message, and removing it has no obvious negative
effect.

https://bugzilla.gnome.org/show_bug.cgi?id=730767

gtk/gtknotebook.c

@@ -2611,7 +2611,7 @@ gtk_notebook_draw (GtkWidget *widget,
             }
         }
 
-      if (priv->cur_page && priv->operation != DRAG_OPERATION_REORDER)
+      if (priv->cur_page)
         gtk_container_propagate_draw (GTK_CONTAINER (notebook),
                                       priv->cur_page->child,
                                       cr);