Backport AS7-4117
https://github.com/jbossas/jboss-as/commit/0284f034540343cd4f710049adc74afb84db5088#ejb3/src/main/java/org/jboss/as/ejb3/pool/strictmax/StrictMaxPool.java
AS7-4117 Intermittent failure in StrictMaxUnitTestCase.testMultiThread()