Multi-View: Fix (unreported) wrong icons for disabled Render Views

This is likely broken since 60cc73afe6, when I sorted the icons
alphabetically.

Multi-View lives on!

scripts/startup/bl_ui/properties_output.py

@@ -627,7 +627,7 @@ class RENDER_UL_renderviews(UIList):
         view = item
         if self.layout_type in {'DEFAULT', 'COMPACT'}:
             if view.name in {"left", "right"}:
-                layout.label(text=view.name, icon_value=icon + (not view.use))
+                layout.label(text=view.name, icon_value=icon - (not view.use))
             else:
                 layout.prop(view, "name", text="", index=index, icon_value=icon, emboss=False)
             layout.prop(view, "use", text="", index=index)