Spring Security Remove OpenSaml deprecation warnings

Expected Behavior

When running Spring Security with saml support it should not log deprecation warnings.

Current Behavior

While using OpenSamlLogoutRequestResolver the application logs for example:

09:09:04 [WARN ] DEPRECATED#warn:125 - Java class method 'setSessionIndex', (interface org.opensaml.saml.saml2.core.SessionIndex): This will be removed in the next major version of this software; replacement is setValue

Context

Deprecated (for removal) methods should not be used any longer. I will provide a PR with a fix.