[stability-pipeline] 2 residues with the same numbering will (likely) cause an error

[j0kaso]

When 2 residues have the same number, e.g. 1igy (https://proteopedia.org/wiki/index.php/Unusual_sequence_numbering), this will likely cause an error for a given prism or mut_file at this position.
mut_mode=all will likely also raise an error (but should not - be fine)

see also https://kull-centre.slack.com/archives/CF4RCEW2C/p1599652047026100?thread_ts=1599563415.008900&cid=CF4RCEW2C

[j0kaso]

issue solved due to renumbering (also tested).