IO.C change for better iPad compatibility

[btaylor84]

https://github.com/tmewett/BrogueCE/blob/f5869113c174c50ec5215d46598c72bcbb0a7234/src/brogue/IO.c#L2789

change the offset from - 1 to - 5 to lift the dialogue up over the iPad's onscreen keyboard. 5 lines up from the center should still work well for other ports