ISPN-5023 Random Failues on *FactoryBeanTest in the Spring Modules

https://issues.jboss.org/browse/ISPN-5023

Wasn't able to reproduce it locally, but I think sometimes there's a clash inside Jgroups Jmx registration, given that the modules run by default on 15 threads. Changed it to 1 Thread, test time is roughly the same in my environment