webadmin: DirectLUN FC - fix radio-buttons behavior

Fixed radio-button single-selection behavior for FC DirectLUN
(added single-selection listeners to FC LunModels for
clearing unselected radio-buttons).

Change-Id: I739adc6da16ca075acd4a3ae6d48e4ad2d8cac79
Bug-Url: https://bugzilla.redhat.com/918568
Signed-off-by: Daniel Erez <derez@redhat.com>