Fixed the headpin nightly failures

Fixed a few failures 

TestClass : 
com.redhat.qe.katello.tests.cli.SystemGroupTests
com.redhat.qe.katello.tests.cli.VersionTest

One of the latest test report : 
http://hudson.rhq.lab.eng.bos.redhat.com:8080/hudson/job/official-headpin-cli/262/ReportNG_Report/

Please review it 
thanks