webadmin: In disks tab/subtab, make the default view to All

In the disks maintab/subtab we have 3 view options - All, Images, LUNs, the
default was "Images" and now was changed to "All"

Bug-Url: https://bugzilla.redhat.com/878962
Signed-off-by: Tal Nisan <tnisan@redhat.com>
Change-Id: I4f97a8c39053eac961a79141071ee3471825f1df