Server can be created on the wrong user

[hwalker928]

The issue lies with the filter present here: https://github.com/pterodactyl/whmcs/blob/master/pterodactyl/pterodactyl.php#L310

If the user's email ends with something that an existing user's email is, then the server is created on the other client's account.

For example, a new client with the email "[email protected]" would get their service created on the existing user who has the email "[email protected]".