saml:SP: Do not return PartialLogout error when unable to terminate all sessions.
saml:SP: Do not return PartialLogout error when unable to terminate all sessions.

cb8/saml2,newmen/saml2,ArtemTeleshev/php-saml2,simplesamlphp/saml2,sgomez/saml2,madmatt/saml2,sitya/saml2