If attachSD fails - rescan for new vgs not visible from spm

Change-Id: I7cb26397d8a38215aaec0287e7882751471a6d61
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=883390
Signed-off-by: Yeela Kaplan <ykaplan@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/10495
Tested-by: Daniel Paikov <paikov@gmail.com>
Reviewed-by: Eduardo <ewarszaw@redhat.com>
Reviewed-by: Ayal Baron <abaron@redhat.com>