Fix #145391: File Output node: "Layers" uilist button is misaligned

Caused by 7d7562e849

Above commit added a `separator_spacer` (for no obvious reason?)
This PR removes it again.

Pull Request: https://projects.blender.org/blender/blender/pulls/145397

source/blender/editors/space_image/image_buttons.cc

@@ -1066,8 +1066,6 @@ void uiTemplateImageSettings(uiLayout *layout,
 
   /* Override color management */
   if (color_management) {
-    col->separator_spacer();
-
     if (uiLayout *panel = col->panel(C,
                                      panel_idname ? panel_idname : "settings_color_management",
                                      true,