Update submissions.js

Fixes for:
* [14:09:36.459] ReferenceError: assignment to undeclared variable refbegin @ https://en.wikipedia.org/w/index.php?action=raw&ctype=text/javascript&title=User:Theo%27s%20Little%20Bot/afch/afchelper.js/submissions.js:1417
* [14:09:36.459] ReferenceError: assignment to undeclared variable refend @ https://en.wikipedia.org/w/index.php?action=raw&ctype=text/javascript&title=User:Theo%27s%20Little%20Bot/afch/afchelper.js/submissions.js:1418