tests: Made unapply_fixes call optional at master uninstallation
    
    Unapply fixes removes the temporary testing folder at ~/ipatests, which
    contains some artifacts like root.pem that need to be persistent between tests
    in the test_caless testsuite. There has to be the way to skip the deletion of
    this testfolder
    
    Reviewed-By: David Kupka <dkupka@redhat.com>