sp: Remove uneeded error handler

domainMointor module does not raise StorageException and handling it
does not help anyone.

Change-Id: Ic540ddb6644e445e2606e752371f1bf635a4227f
Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/27713
Reviewed-by: Antoni Segura Puimedon <asegurap@redhat.com>
Reviewed-by: Federico Simoncelli <fsimonce@redhat.com>