Fixed Column 'sys_userid' cannot be null error when adding website as admin without choosing a client.

Fixes #4972 Domain in spamfilter_user settings not punicode encoded

Fixed #4052 open_basedir contains client0 where it should contain client1 when value is taken from System default

if the filter rule uses "begins with", the regex should be "^$searchterm" instead of " $searchterm"

FS#2006 - IPv6 Support for V-Server