Switch the default depth for Core::GoBack to 1 instead of 2.
Switch the default depth for Core::GoBack to 1 instead of 2.

This is due to the minor change in its backend logic.

nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus