Testsuite calls to low-level reload ops should deal with CancellationExc...

...eption as it can happen if the channel gets closed

This will fix reload failures like the CertificateRolesLoginModuleTestCase ones in http://brontes.lab.eng.brq.redhat.com/viewLog.html?buildId=29836&buildTypeId=WildFlyCore_PullRequest_WildFlyCoreFullIntegration