Update URLs and check SSL cert

Hello! (Veuillez pardonner mon Anglais; Dites-moi si je dois trouver un francophone collègue) Thanks very much for implementing Persona! We changed the domain, so I thought you might like to update. Cheers, Sam

ps It looks like you also own https://github.com/Rudloff/mybb-browserid/blob/master/browserid.php, which also needs an update.