Oh don't we love all the chainline problems

does the chainstay already have a dent for clearance? if so you can make it bigger (did that on my MTB conversion) if not you can make a dent for more clearance, or go for a wider rear hub, the londonfixiebike shimano bolt on jobbies give a dishless wheel with 46mm chainline using a 10mm spacer each side.

yep I go with this advice make the crimp bigger or new hub. To make the crimp bigger you can either make a crimper or use a (ideally shaped) block of wood behind the chainstay for non denting support and a cold chisel.