Fieldable Panels Pane entities may not have their 'reusable' option changed

Fieldable Panels Panes (FPP) provides an entity type with custom integration with the Panels module suite. One of the options when creating a new FPP entity is to control whether that entity may be embedded on multiple Panels displays or just the current one the entity is being added to. Prior to the current release it was possible to change this option after an FPP entity was created. In the interest of avoiding problems with editorial workflows, this option has been removed. As a result, an FPP entity's reusability may not be changed after it is initially created.