#346 Post-Python 3: Submit Make Pseudo doesn't validate child author ID

[Ahasuerus]

edit/submitmkpseudo.py uses the value of author_id (child author ID) to load author_data from the database, but it doesn't validate the load was successful. Normally, it shouldn't be an issue because "author_id" is a hidden value in the HTML form, so it should always be valid. However, if the author record was deleted between the time the HTML form was emitted and the "Submit" button was clicked (or if the HTML form was manually changed), this will result in a Python error.