ethsign doesn't seem to like when \n characters are included in the message

[vcavallo]

We should not deal with this (or at least not merge a fix) until after our current experiment concludes.

everything else being equal, this message fails signature verification:

Welcome to your appliance!\n\nSign this message to log in.\n\nThis request will not trigger a blockchain transaction or cost any gas fees.

while this one passes:

Welcome to your appliance! Sign this message to log in. This request will not trigger a blockchain transaction or cost any gas fees.