Exclude Servlet 3.1 transitive dependency from JACC API dependency

As a follow-up to WFLY-11573 we could exclude transitive Servlet 3.1 dependency in wildfly-core project from jboss-jacc-api_1.5_spec dependency.

While jboss-jacc-api_1.5_spec depends on jboss-servlet-api-3.1-spec and we are trying to remove the depedency without providing another one, this still should be correct:

1) testsuite passes with the exclusion in place, ie. the classes from Servlet 3.1 aren't used here
2) both feature and galleon pack excludes it too
https://github.com/wildfly/wildfly-core/blob/master/core-feature-pack/pom.xml#L117-L126
https://github.com/wildfly/wildfly-core/blob/master/core-galleon-pack/pom.xml#L120-L129
3) the module contains it as optional dependency
https://github.com/wildfly/wildfly-core/blob/master/core-feature-pack/src/main/resources/modules/system/layers/base/javax/security/jacc/api/main/module.xml#L27