Suppress attached maps from the Recent Files list

A MindManager map may be embedded in another map as an attachment. When an attached map is opened, it gets added to the Recent Files list shown in File > Open. The location of the map is somewhere in the user's temp folder. Clicking on these links usually says the file is no longer available, because normal handling of attachments deletes the temporary copy on close. It would be better to suppress attached maps from the Recent Files list altogether.