remove the now-redundant main-doc option
remove the now-redundant main-doc option

svn: r8288

original commit: fff894d7100add97eddfe8f965e7c1f558abd87c

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket