(7.1.z) JACC is broken after server reload

It was discovered by https://github.com/wildfly/wildfly/pull/10829 that JACC has problems after server reload.

org.jboss.security.jacc.JBossPolicyConfigurationFactory will always use the first 'org.jboss.security.jacc.DelegatingPolicy' that is set, while on reload org.jboss.as.security.service.SecurityBootstrapService will create and install a new policy, which means that after you execute a reload operation JACC is broken (provided the JBossPolicyConfigurationFactory was initialised before the reload).

This will need to be fixed somehow, either by using the same DelegatingPolicy after reload, or by clearing the state in JBossPolicyConfigurationFactory.