`SomeUnsignedInt` arguments silently wrap

[tersec]

import confutils

type
  Command = enum
    noCommand

  IntConf = object
    case cmd {.
      command
      defaultValue: noCommand }: Command

    of noCommand:
      uint8Arg: uint8
      uint16Arg: uint16
      uint32Arg: uint32

let conf = IntConf.load()
echo "uint8Arg = ", conf.uint8Arg
echo "uint16Arg = ", conf.uint16Arg
echo "uint32Arg = ", conf.uint32Arg

$ ./env.sh nim c -r --hints:off -o:$(mktemp) intconf.nim --uint8Arg=256 --uint16Arg=65536 --uint32Arg=4294967296
uint8Arg = 0
uint16Arg = 0
uint32Arg = 0
$ ./env.sh nim c -r --hints:off -o:$(mktemp) intconf.nim --uint8Arg=257 --uint16Arg=65537 --uint32Arg=4294967297
uint8Arg = 1
uint16Arg = 1
uint32Arg = 1