message: nit: use a `1` literal directly
diff: @@ -692,8 +692,7 @@ fn div_rem_core(mut a: BigUint, b: &BigUint) -> (BigUint, BigUint) {
  let mut prod = b * &q0;
  while cmp_slice(&prod.data[..], &a.data[j..]) == Greater {
  - let one: BigDigit = 1;
  - q0 -= one;
  + q0 -= 1u32;
  prod -= b;
  }
  