Allow for configuration of 5.0's zabbix.conf.php SAML settings

[James Kirsop]

5.0 introduced some new settings that are managed via zabbix.conf.php including those for SAML authentication. On a CentOS 7 installation this file is located in /etc/zabbix/web.

These would be added to the zabbix::web class.

Particular configuration settings to manage:

$SSO['SP_KEY'] = '<path to the SP private key file>';
$SSO['SP_CERT'] = '<path to the SP cert file>';
$SSO['IDP_CERT'] = '<path to the IDP cert file>';
$SSO['SETTINGS']

Reference: https://www.zabbix.com/documentation/current/manual/web_interface/frontend_sections/administration/authentication#saml_authentication

[Anthony Somerset]

there is also a DB config value relating to the DB in the 5.0 upgrade

https://www.zabbix.com/documentation/current/manual/installation/upgrade_notes_500 - Enabling extended range of numeric (float) values