V10: DisableIndentity should be DisableIdentity

[chayim]

As part of the SETINFO changes in #2915, we noticed that the option is set as DisableIndentity rather than DisableIdentity. In order to ensure fewer breaking changes, this option should be renamed, ideally in V10.

[ndyakov]

Marked as deprecated and new DisableIdentity has been introduced. Will be completely removed in v10