Hi @pifane,
As it turns out, the fix is quite easy. And I have to thank @jsusoy for helping me discover the issue.
Please download and extract this file. And then upload the two files (pwreset.login.php and pwreset.sent.php) to include/client/, overwriting the files that are currently on your server.
Or you can wait and upgrade to one of the new releases that will be coming out shortly to catch up with osTicket 1.14.4 and 1.15.