Update Errai version from 2.4.1.Final to 2.4.3.Final
This new version is just for bug fixes, here a complete list them:
https://issues.jboss.org/browse/ERRAI-673?jql=project%20%3D%20ERRAI%20AND%20fixVersion%20in%20(%222.4.2.Final%22%2C%20%222.4.3.Final%22)

Note: ERRAI-671 - Build/Compilation hangs when running with only one CPU is very annoying, we see this error all the time on our CI and on our developer's machine as well.