Selectors in written books require player to be operator to work

The bug

Usage of selectors in books don't work, unless the player being given the book is an operator. Basically, let's say you have such a command:

/give @a written_book[written_book_content={title:"Example",author:"someone",pages:['{"selector":"@s"}']}] 1

When the command block is powered, a player who is an operator will receive a book, which on its first page will have their IGN printed. A player who is NOT an operator will receive a book with an empty first page.