Output GFA missing unitigs in S lines

[atabeerk]

In the output GFA file (strainy_final.gfa), some unitigs in L lines do not have corresponding S lines. This may be due to attempting to remove the unitigs at some point (and removing their S lines) but forgetting to remove the L lines in which these unitigs are used.

The attached file is the output of the mock ONT dataset. Some unitigs that have that issue: edge_1291_139, edge_956_40, edge_874_33, edge_3054_s1_3041692, edge_3024_11380, edge_1553_1030193, edge_2864_1000769