iSCSI: test user authentication
    
    Summary:
    This isn't in the criteria, but it's commonly used, so we ought
    to test this way. Require authentication for the iSCSI target
    and have the test provide the appropriate auth info.
    
    Test Plan:
    Run the iscsi test and check it works (you need the
    recent fixes for support_server to make *that* work). Nothing
    else should be affected.
    
    Reviewers: jskladan, garretraziel
    
    Reviewed By: garretraziel
    
    Subscribers: tflink
    
    Differential Revision: https://phab.qadevel.cloud.fedoraproject.org/D1070