message: fix: properly detect range of length 1
diff: @@ -12,7 +12,7 @@ namespace Nextclade {
  // but bioinformaticians prefer 1-based, closed ranges
  const auto beginOne = range.begin + 1;
  const auto endOne = range.end;
  - if (endOne - beginOne == 1) {
  + if (endOne == beginOne) {
  return std::to_string(beginOne);
  }
  return fmt::format("{}-{}", beginOne, endOne);
  