compare to negative strand for dna_start_t_withstop

tool                    TP         FP         TN         FN       prec      sens      spec       NPV       MCC
FGS                2494195     231257     656879     283010      91.51     89.81     73.96     69.89     62.58
FGS+               2661256     533556     361341     109188       83.3     96.06     40.38     76.79     46.79
prodigal           2488137     117535     745673     313996      95.49     88.79     86.38     70.37     70.36
FGSrs              2494195     231257     656879     283010      91.51     89.81     73.96     69.89     62.58

src/viterbi.rs

@@ -616,7 +616,7 @@ fn build_genes(
             dna.push(seq[t]);
             dna_start_t_withstop = t + 1;
             dna_start_t = t + 1;
-            if vpath[t] == hmm::State::M1 || vpath[t] == hmm::State::M4r {
+            if vpath[t] == hmm::State::M1r || vpath[t] == hmm::State::M4r {
                 if t > 2 {
                     dna_start_t_withstop = t - 2;
                 }