Possible mistake (bad copy paste)

[Bbulatov]

Hello!
During the static analysis was found possible bad copy paste:

1. In schema.go:863-879 using only KEY_ANY_OF, but in schema.go:881-897 using KEY_ALL_OF and using KEY_ANY_OF in schema.go:894. Please, clarify, must be in schema.go:894 KEY_ALL_OF instead of KEY_ANY_OF or no?