full_name preference not quoted in email send

The full_name preference is not quoted in the Envelope when sending. This only appears to be a problem when there are special characters, the most notable being a comma. It is not unusual for someone to use "lastname, firstname" for a full_name preference.

Fix in utils/config_check.php

// Append name if known
// if(!empty($user_prefs->full_name))
// $from_address = $user_prefs->full_name . ' <' . $from_address . '>';
if(!empty($user_prefs->full_name))
$from_address = '"' . $user_prefs->full_name . '"' . ' <' . $from_address . '>';