message: fix: account for the fact that the length of the gene can be different from %3 before stripping
diff: @@ -79,10 +79,11 @@ void stripGeneInPlace(NucleotideSequence& seq) {
  }
  }
  + const auto& final_frame = length%3;
  // Find the last non-GAP nucleotide and replace GAPs in the corresponding codon with Ns, so that it's not getting stripped
  for (int i = length - 1; i >= 0; --i) {
  if (at(seqSpan, i) != Nucleotide::GAP) {
  - const auto codonBegin = i - i % 3;
  + const auto codonBegin = i - (i - final_frame) % 3;
  invariant_greater_equal(codonBegin, 0);
  invariant_less(codonBegin + 2, length);
  