filters: Unpack the user information before filter

If a user is created / selected before opening a ticket (very likely the
case in the SCP), the email address and name should be unpacked into the
$vars dictionary prior to creating and processing ticket filters
Merge pull request #425 from greezybacon/issue/filter-deny-scp

filters: Unpack the user information before filter

Reviewed-By: Peter Rotich <peter@osticket.com>